CN107764197A - A kind of optical system axial direction parameter measuring apparatus and method - Google Patents
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Abstract
本发明公开了一种光学系统轴向参数测量装置及方法，该装置包括：低相干测量单元、高相干标尺单元、扫描单元、量程倍增单元和信号处理单元，低相干测量单元用于产生低相干干涉波；高相干标尺单元用于产生高相干干涉波；低相干参考光和高相干测量光均经过扫描单元，扫描单元用于为低相干干涉波和高相干干涉波提供同一光学延时线；量程倍增单元用于采集低相干测量单元产生的低相干干涉波以及扩大测量量程的范围；信号处理单元用于以高相干干涉波为参考基准，对量程倍增单元采集到的低相干干涉波进行分析处理，得到光学系统各介质分界面之间的轴向距离。本发明提供的光学系统轴向参数测量装置及方法具有测量范围大、信噪比高、测量快速准确的特点。
The invention discloses a device and method for measuring axial parameters of an optical system. The device includes: a low-coherence measurement unit, a high-coherence scale unit, a scanning unit, a range multiplication unit and a signal processing unit. The low-coherence measurement unit is used to generate low-coherence Interference waves; the high-coherence scale unit is used to generate high-coherence interference waves; the low-coherence reference light and the high-coherence measurement light both pass through the scanning unit, and the scanning unit is used to provide the same optical delay line for the low-coherence interference wave and the high-coherence interference wave; The range multiplication unit is used to collect the low coherence interference wave generated by the low coherence measurement unit and expand the range of the measurement range; the signal processing unit is used to analyze the low coherence interference wave collected by the range multiplication unit with the high coherence interference wave as a reference Processing to obtain the axial distance between the interface of each medium in the optical system. The optical system axial parameter measurement device and method provided by the invention have the characteristics of large measurement range, high signal-to-noise ratio, and rapid and accurate measurement.
Description
技术领域technical field
本发明涉及光学测量领域，特别是涉及一种光学系统轴向参数测量装置及方法。The invention relates to the field of optical measurement, in particular to an optical system axial parameter measurement device and method.
背景技术Background technique
对应光学系统轴向参数的测量，现有技术中一般采用以下两种系统：一种系统记载于"High stability multiplexed fibre interferometer and its application onabsolute displacement measurement and on-line surface metrology”，OpticsExpress,Vol.12，Issue 23,2004,P.5729-5734.(Optics Express(光学特快)，2004年，第12卷，第23期，P.5729-5734)中，此系统包含两个光路几乎重合的迈克尔逊干涉仪。半导体激光器发出波长为λ0的光经过一个迈克尔逊干涉仪后被探测器探测，此探测器探测到的信号经过伺服电路处理后驱动压电陶瓷管调节光纤干涉仪的参考臂的长度，实现稳定该干涉仪的目的，可调谐激光器发出的波长λm可变的光经过另一个迈克尔逊干涉仪后被探测器探测，再经过相位分析即测量出测量镜的位移。利用测量镜和参考镜作为反射镜的构成，用于完成测量工作。另一种系统将一个光纤干涉仪(传感光纤干涉仪)Ml置于被测场感应被测位移，用另一个与传感光纤干涉仪Ml串联的光纤干涉仪(解调光纤干涉仪)M2解调位移的值，从而对位移实现远程测量。基于波分复用技术，利用光纤光栅反射满足布拉格条件的波长的光，使解调光纤干涉仪M2同时工作在低相干干涉和高相干干涉状态，利用低相干干涉信号决定位移的幅值，使测量量程不受光波波长限制，并实现绝对测量，利用高相干干涉信号测量位移的值，并利用反馈控制抑制环境干扰对解调光纤干涉仪M2的影响，实现高精度测量。Corresponding to the measurement of the axial parameters of the optical system, the following two systems are generally used in the prior art: one system is described in "High stability multiplexed fiber interferometer and its application on absolute displacement measurement and on-line surface metrology", OpticsExpress, Vol.12 , Issue 23, 2004, P.5729-5734. (Optics Express (Optics Express), 2004, Vol. 12, No. 23, P.5729-5734), this system contains two Michelson interferometer. The light emitted by the semiconductor laser with a wavelength of λ0 passes through a Michelson interferometer and is detected by the detector. The signal detected by the detector is processed by the servo circuit and drives the piezoelectric ceramic tube to adjust the length of the reference arm of the fiber optic interferometer to achieve stability. The purpose of the interferometer is that the light emitted by the tunable laser with a variable wavelength λm passes through another Michelson interferometer and then detected by the detector, and then the displacement of the measuring mirror is measured through phase analysis. The measuring mirror and the reference mirror are used as reflective mirrors to complete the measurement work. Another system puts an optical fiber interferometer (sensing optical fiber interferometer) M1 in the measured field to sense the measured displacement, and uses another optical fiber interferometer (demodulation optical fiber interferometer) M2 connected in series with the sensing optical fiber interferometer M1 The value of the displacement is demodulated to enable remote measurement of the displacement. Based on the wavelength division multiplexing technology, the optical fiber grating is used to reflect the light of the wavelength that satisfies the Bragg condition, so that the demodulation fiber interferometer M2 works in the low coherent interference and high coherent interference states at the same time, and the amplitude of the displacement is determined by the low coherent interference signal, so that The measurement range is not limited by the wavelength of the light wave, and absolute measurement is realized. The value of displacement is measured by using highly coherent interference signals, and feedback control is used to suppress the influence of environmental interference on the demodulation fiber optic interferometer M2 to achieve high-precision measurement.
但是，以上两个系统均存在测量量程受限的问题，第一种系统中量程受入射光波波长入的限制，且不能进行绝对测量；第二种系统中量程受到一维台的行程限制。However, both of the above two systems have the problem of limited measurement range. In the first system, the range is limited by the wavelength of the incident light, and absolute measurement cannot be performed; in the second system, the range is limited by the stroke of the one-dimensional stage.
发明内容Contents of the invention
本发明的目的是提供一种光学系统轴向参数测量装置及方法，具有测量范围大、信噪比高、测量快速准确的特点。The purpose of the present invention is to provide a measuring device and method for axial parameters of an optical system, which has the characteristics of large measuring range, high signal-to-noise ratio, and rapid and accurate measurement.
为实现上述目的，本发明提供了如下方案：To achieve the above object, the present invention provides the following scheme:
一种光学系统轴向参数测量装置，所述装置包括：A device for measuring axial parameters of an optical system, the device comprising:
低相干测量单元，所述低相干测量单元用于产生低相干干涉波；所述低相干测量单元包括低相干光源，所述低相干光源发出低相干测量光和低相干参考光，所述低相干干涉波为所述低相干测量光经过被测光学系统反射后的光与所述低相干参考光干涉形成的光波；A low coherence measurement unit, the low coherence measurement unit is used to generate low coherence interference waves; the low coherence measurement unit includes a low coherence light source, the low coherence light source emits low coherence measurement light and low coherence reference light, the low coherence The interference wave is a light wave formed by interference between the low-coherence measurement light reflected by the measured optical system and the low-coherence reference light;
高相干标尺单元，所述高相干标尺单元用于产生高相干干涉波；所述高相干标尺单元包括高相干光源，所述高相干光源发出高相干测量光和高相干参考光，所述高相干测量光和高相干参考光发生干涉，形成高相干干涉波；A high-coherence scale unit, the high-coherence scale unit is used to generate high-coherence interference waves; the high-coherence scale unit includes a high-coherence light source, and the high-coherence light source emits high-coherence measurement light and high-coherence reference light, and the high-coherence Measuring light interferes with highly coherent reference light to form highly coherent interference waves;
扫描单元，所述低相干参考光和所述高相干测量光均经过所述扫描单元，所述扫描单元用于为所述低相干干涉波和所述高相干干涉波提供同一光学延时线；a scanning unit, the low-coherence reference light and the high-coherence measurement light both pass through the scanning unit, and the scanning unit is used to provide the same optical delay line for the low-coherence interference wave and the high-coherence interference wave;
量程倍增单元，所述量程倍增单元用于采集所述低相干测量单元产生的所述低相干干涉波以及扩大测量量程的范围；a range multiplication unit, the range multiplication unit is used to collect the low-coherence interference wave generated by the low-coherence measurement unit and expand the range of the measurement range;
信号处理单元，所述信号处理单元用于以所述高相干干涉波为参考基准，对量程倍增单元采集到的所述低相干干涉波进行分析处理，得到光学系统各介质分界面之间的轴向距离；A signal processing unit, the signal processing unit is used to analyze and process the low-coherence interference wave collected by the range multiplication unit with the high-coherence interference wave as a reference, and obtain the axis between the medium interfaces of the optical system to the distance;
所述低相干测量单元与所述量程倍增单元相连接，所述信号处理单元分别与所述量程倍增单元、所述高相干标尺单元相连接。The low-coherence measurement unit is connected to the range multiplication unit, and the signal processing unit is respectively connected to the range multiplication unit and the high-coherence scale unit.
可选的，所述低相干测量单元还包括第一耦合器、第一偏振控制器、第一光环形器、第一准直器、第二偏振控制器、第二光环形器、波分复用器、第二准直器；Optionally, the low-coherence measurement unit further includes a first coupler, a first polarization controller, a first optical circulator, a first collimator, a second polarization controller, a second optical circulator, a wavelength division multiplexing Use device, second collimator;
所述低相干测量光经由第一偏振控制器、第一光环形器、第一准直器后依次入射到被测光学系统的各介质分界面上，经各介质分界面反射后依次经过所述第一光环形器、所述第一光纤分路器，依次到达所述量程倍增单元；所述低相干测量光经过所述第一光纤分路器后得到的多路低相干测量光；The low-coherence measurement light is sequentially incident on each medium interface of the optical system under test after passing through the first polarization controller, the first optical circulator, and the first collimator, and is reflected by each medium interface and then sequentially passes through the The first optical circulator and the first optical fiber splitter sequentially reach the range multiplication unit; the low-coherence measurement light is multi-channel low-coherence measurement light obtained after passing through the first optical fiber splitter;
所述低相干参考光经由第二偏振控制器、第二光环形器、波分复用器、第二准直器、所述扫描单元的扫描镜，垂直入射到所述扫描单元的反射镜，经所述扫描单元的反射镜反射后返回到达所述第二光环形器，经所述第二光环形器、第二光纤分路器到达所述量程倍增单元；所述低相干参考光经过所述第二光纤分路器后得到的多路低相干参考光，相邻光路中的低相干参考光的光程成等差数列；The low-coherence reference light is vertically incident on the mirror of the scanning unit via the second polarization controller, the second optical circulator, the wavelength division multiplexer, the second collimator, and the scanning mirror of the scanning unit, After being reflected by the mirror of the scanning unit, it returns to the second optical circulator, and then reaches the range multiplication unit through the second optical circulator and the second optical fiber splitter; the low coherence reference light passes through the The multi-channel low-coherence reference light obtained after the second optical fiber splitter, the optical path of the low-coherence reference light in adjacent optical paths forms an arithmetic sequence;
所述低相干测量光经过所述第一光纤分路器后得到的多路低相干测量光与所述低相干参考光经过所述第一光纤分路器后得到的多路低相干测量光在所述量程倍增单元发生干涉，得到所述低相干干涉波。The multi-channel low-coherence measurement light obtained after the low-coherence measurement light passes through the first optical fiber splitter and the multi-channel low-coherence measurement light obtained after the low-coherence reference light passes through the first optical fiber splitter Interference occurs in the range multiplication unit to obtain the low-coherence interference wave.
可选的，所述量程倍增单元包括多个耦合器、与各所述耦合器一一对应的探测器对，所述低相干测量光和所述低相干参考光在所述量程倍增单元的所述耦合器处发生干涉，得到所述低相干干涉波；所述探测器对对所述耦合器输出的所述低相干干涉波进行探测，所述低相干干涉波包括低相干反射干涉波和低相干透射干涉波。Optionally, the range doubling unit includes a plurality of couplers and a pair of detectors corresponding to each of the couplers, and the low-coherence measurement light and the low-coherence reference light pass through the range doubling unit. Interference occurs at the coupler to obtain the low-coherence interference wave; the detector detects the low-coherence interference wave output by the coupler, and the low-coherence interference wave includes low-coherence reflection interference wave and low-coherence interference wave Coherently transmitted interference waves.
可选的，所述探测器对包括两个探测器，两个所述探测器分别用于对所述低相干反射干涉波和所述低相干透射干涉波进行探测。Optionally, the detector pair includes two detectors, and the two detectors are respectively used to detect the low-coherence reflection interference wave and the low-coherence transmission interference wave.
可选的，所述高相干标尺单元包括高相干光源、第三耦合器、第四耦合器、第四耦合器、第三光环形器、第四光环形器和端面镀反射膜的光纤；Optionally, the high-coherence scale unit includes a high-coherence light source, a third coupler, a fourth coupler, a fourth coupler, a third optical circulator, a fourth optical circulator, and an optical fiber coated with a reflective film;
所述高相干光源发出的光经过所述第三耦合器后分成高相干参考光和高相干测量光，所述高相干参考光经由所述第三光环形器、端面镀反射膜的光纤、所述第三光环形器后到达所述第四耦合器，所述高相干测量光经由第四光环形器、波分复用器、第二准直器、所述扫描单元的扫描镜、垂直入射到所述扫描单元的反射镜，经扫描单元的反射镜反射后原路返回到达所述第四光环形器，经所述第四光环形器后到达所述第四耦合器；The light emitted by the high-coherence light source is divided into high-coherence reference light and high-coherence measurement light after passing through the third coupler. After the third optical circulator reaches the fourth coupler, the highly coherent measurement light passes through the fourth optical circulator, wavelength division multiplexer, second collimator, scanning mirror of the scanning unit, vertical incidence To the mirror of the scanning unit, after being reflected by the mirror of the scanning unit, return to the fourth optical circulator in the same way, and then reach the fourth coupler after passing through the fourth optical circulator;
入射到所述第四耦合器的所述高相干参考光和高相干测量光发生干涉，得到高相干干涉波，所述高相干干涉波包括高相干反射干涉波和高相干透射干涉波。The highly coherent reference light incident on the fourth coupler interferes with the highly coherent measurement light to obtain a highly coherent interference wave, and the highly coherent interference wave includes a highly coherent reflection interference wave and a highly coherent transmission interference wave.
可选的，所述高相干标尺单元还包括两个探测器，两个所述探测器分别用于对所述第四耦合器输出的所述高相干反射干涉波和所述高相干透射干涉波进行探测。Optionally, the high-coherence scale unit further includes two detectors, and the two detectors are respectively used to detect the high-coherence reflection interference wave and the high-coherence transmission interference wave output by the fourth coupler. Probing.
可选的，各光学器件之间的均采用光纤或光纤器件相连接。Optionally, optical fibers or optical fiber devices are used to connect optical devices.
本发明还提供了一种光学系统轴向参数测量方法，所述方法应用于本发明提供的光学系统轴向参数测量装置，所述方法包括：The present invention also provides a method for measuring an axial parameter of an optical system, the method is applied to the device for measuring an axial parameter of an optical system provided by the present invention, and the method includes:
闭合光学系统轴向参数测量装置的总电源，点亮高相干光源、低相干光源；Close the total power supply of the axial parameter measuring device of the optical system, and turn on the high-coherence light source and the low-coherence light source;
前后移动被测光学系统，当被测光学系统第一个介质分界面的干涉峰出现在量程倍频单元中的第一组探测器上时，固定被测光学系统；Move the optical system under test back and forth, and fix the optical system under test when the interference peak of the first medium interface of the optical system under test appears on the first group of detectors in the range frequency doubling unit;
量程倍增单元中各组探测器接收被测光学系统各分界面处的低相干干涉信号；Each group of detectors in the range doubling unit receives low-coherence interference signals at each interface of the measured optical system;
信号处理单元采用微分过零法提取所述低相干干涉信号的极大值点，获取被测光学系统各分界面位置信息，并根据信号处理单元显示的干涉波图形，以高相干标尺单元产生的高相干干涉波为参考计算被测光学系统各分界面之间的距离，所述干涉波图形包括低相干干涉波图形和高相干干涉波图形。The signal processing unit uses the differential zero-crossing method to extract the maximum point of the low-coherence interference signal, obtains the position information of each interface of the optical system under test, and according to the interference wave pattern displayed by the signal processing unit, uses the high-coherence scale unit to generate The high-coherence interference wave is used as a reference to calculate the distance between the interfaces of the measured optical system, and the interference wave pattern includes a low-coherence interference wave pattern and a high-coherence interference wave pattern.
可选的，所述根据信号处理单元显示的干涉波图形，以高相干标尺单元产生的高相干干涉波为参考计算被测光学系统各分界面之间的距离，具体包括：Optionally, according to the interference wave pattern displayed by the signal processing unit, the distance between the interfaces of the optical system under test is calculated with reference to the high coherence interference wave generated by the high coherence scale unit, specifically including:
当相邻两个介质分界面对应的低相干干涉信号处在同一个探测器上时，利用公式计算相邻两个介质分界面的轴向距离，其中，d为相邻两个介质分界面的轴向距离；n为干涉波图形中相邻两个介质分界面对应的低相干干涉信号的最大值之间包含高相干干涉信号周期的个数，λ为高相干光源发出光的波长；When the low-coherence interference signals corresponding to the interface between two adjacent media are on the same detector, the formula Calculate the axial distance between two adjacent medium interfaces, where d is the axial distance between two adjacent medium interfaces; n is the maximum value of the low-coherence interference signal corresponding to two adjacent medium interfaces in the interference wave pattern The values include the number of high-coherence interference signal cycles, and λ is the wavelength of light emitted by the high-coherence light source;
当相邻两个介质分界面对应的低相干干涉信号不在同一个探测器上时，利用公式计算相邻两个介质分界面的轴向距离，其中，d为相邻两个介质分界面的轴向距离；nm为干涉波图形中前一介质分界面对应的低相干干涉信号的最大值与高相干干涉信号起始值之间包含高相干涉信号周期的个数；nn为干涉波图形中后一介质分界面对应的低相干干涉信号的最大值与高相干涉信号起始值之间包含高相干干涉信号周期的个数；Lm、Ln分别为前一介质分界面和后一介质分界面所对应的低相干参考光路的光程；λ为高相干光源发出光的波长。When the low-coherence interference signals corresponding to two adjacent medium interfaces are not on the same detector, use the formula Calculate the axial distance between two adjacent medium interfaces, where d is the axial distance between two adjacent medium interfaces; n m is the maximum value of the low-coherence interference signal corresponding to the previous medium interface in the interference wave pattern The number of cycles of the high-phase interference signal included between the initial value of the high-coherence interference signal; n n is the difference between the maximum value of the low-coherence interference signal corresponding to the latter medium interface in the interference wave pattern and the initial value of the high-phase interference signal The interval includes the number of high-coherence interference signal periods; L m and L n are the optical paths of the low-coherence reference optical paths corresponding to the previous medium interface and the latter medium interface respectively; λ is the wavelength of light emitted by the high-coherence light source.
根据本发明提供的具体实施例，本发明公开了以下技术效果：本发明提供的测量光学系统轴向参数的装置及方法，设置了低相干测量单元、高相干标尺单元、扫描单元、量程倍增单元和信号处理单元，所述低相干测量单元用于产生低相干干涉波，所述高相干标尺单元用于产生高相干干涉波，所述低相干参考光和所述高相干测量光均经过所述扫描单元，使所述低相干干涉波和所述高相干干涉波提供同一光学延时线，通过设置所述量程倍增单元增加了装置的测量范围，信号处理单元，所述信号处理单元用于以所述高相干干涉波为参考基准，对量程倍增单元采集到的所述低相干干涉波进行分析处理，得到光学系统各介质分界面之间的轴向距离，此外，本发明提供的装置中采用的探测器为差分探测器，提高了测量信号的信噪比，能够实现对信号准确的测量。According to the specific embodiment provided by the present invention, the present invention discloses the following technical effects: The device and method for measuring the axial parameters of the optical system provided by the present invention are provided with a low-coherence measurement unit, a high-coherence scale unit, a scanning unit, and a range multiplication unit and a signal processing unit, the low-coherence measuring unit is used to generate low-coherence interference waves, the high-coherence scale unit is used to generate high-coherence interference waves, the low-coherence reference light and the high-coherence measurement light both pass through the A scanning unit, so that the low-coherence interference wave and the high-coherence interference wave provide the same optical delay line, the measurement range of the device is increased by setting the range multiplication unit, and the signal processing unit is used for The high-coherence interference wave is used as a reference, and the low-coherence interference wave collected by the range multiplication unit is analyzed and processed to obtain the axial distance between the interface of each medium in the optical system. In addition, the device provided by the present invention adopts The detector is a differential detector, which improves the signal-to-noise ratio of the measurement signal and enables accurate measurement of the signal.
附图说明Description of drawings
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.
图1为本发明实施例光学系统轴向参数的测量装置的原理图；Fig. 1 is the schematic diagram of the measuring device of the axial parameter of the optical system of the embodiment of the present invention;
图2为本发明实施例高相干标尺单元产生的高相干干涉波形图；FIG. 2 is a high-coherence interference waveform diagram generated by a high-coherence scale unit according to an embodiment of the present invention;
图3为本发明实施例低相干测量单元产生的低相干干涉波形图；3 is a low-coherence interference waveform diagram generated by a low-coherence measurement unit according to an embodiment of the present invention;
图4为本发明实施例被测光学系统相邻分界面在相同探测器上时的测量示意图；Fig. 4 is the measurement schematic diagram when the adjacent interface of the measured optical system is on the same detector according to the embodiment of the present invention;
图5为本发明实施例被测光学系统相邻分界面位置在不同探测器上时一分界面位置的测量示意图；Fig. 5 is a schematic diagram of measuring the position of an interface when the positions of the adjacent interfaces of the measured optical system are on different detectors according to an embodiment of the present invention;
图6为本发明实施例被测光学系统相邻分界面位置在不同探测器上时另一分界面位置的测量示意图；Fig. 6 is a schematic diagram of measuring the position of another interface when the position of the adjacent interface of the measured optical system is on a different detector according to the embodiment of the present invention;
图7为本发明实施例量程倍增单元中等差光纤光程差的标定图；7 is a calibration diagram of the optical path difference of the differential optical fiber in the range multiplication unit of the embodiment of the present invention;
图8为本发明实施例光学系统轴向参数的测量方法的流程示意图。FIG. 8 is a schematic flowchart of a method for measuring axial parameters of an optical system according to an embodiment of the present invention.
具体实施方式Detailed ways
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.
本发明的目的是提供一种光学系统轴向参数测量装置及方法，具有测量范围大、信噪比高、测量快速准确的特点。The purpose of the present invention is to provide a measuring device and method for axial parameters of an optical system, which has the characteristics of large measuring range, high signal-to-noise ratio, and rapid and accurate measurement.
为使本发明的上述目的、特征和优点能够更加明显易懂，下面结合附图和具体实施方式对本发明作进一步详细的说明。In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
图1为本发明实施例光学系统轴向参数的测量装置的原理图，如图1所示，本发明提供的光学系统轴向参数测量装置包括：Fig. 1 is the schematic diagram of the measuring device of the axial parameter of the optical system of the embodiment of the present invention, as shown in Fig. 1, the measuring device of the axial parameter of the optical system provided by the present invention comprises:
低相干测量单元1，所述低相干测量单元1用于产生低相干干涉波；所述低相干测量单元1包括低相干光源101，所述低相干光源101发出低相干测量光和低相干参考光，所述低相干干涉波为所述低相干测量光经过被测光学系统106反射后的光与所述低相干参考光干涉形成的光波；低相干光源发出的光为光谱的宽度较宽，相干长度很短的光，近似于复合色光，不是单一色光；Low-coherence measurement unit 1, the low-coherence measurement unit 1 is used to generate low-coherence interference waves; the low-coherence measurement unit 1 includes a low-coherence light source 101, and the low-coherence light source 101 emits low-coherence measurement light and low-coherence reference light , the low-coherence interference wave is a light wave formed by the interference of the low-coherence measurement light reflected by the measured optical system 106 and the low-coherence reference light; the light emitted by the low-coherence light source has a wide spectrum width and is coherent The light with very short length is similar to composite color light, not single color light;
高相干标尺单元2，所述高相干标尺单元2用于产生高相干干涉波；所述高相干标尺单元2包括高相干光源201，所述高相干光源201发出高相干测量光和高相干参考光，所述高相干测量光和高相干参考光发生干涉，形成高相干干涉波；高相干光源发出的光为光谱的宽度较窄，相干长度很长的单一色光。A high-coherence scale unit 2, which is used to generate high-coherence interference waves; the high-coherence scale unit 2 includes a high-coherence light source 201, and the high-coherence light source 201 emits high-coherence measurement light and high-coherence reference light , the highly coherent measuring light interferes with the highly coherent reference light to form a highly coherent interference wave; the light emitted by the highly coherent light source is a monochromatic light with a narrow spectrum width and a long coherence length.
扫描单元3，所述低相干参考光和所述高相干测量光均经过所述扫描单元3，所述扫描单元3用于为所述低相干干涉波和所述高相干干涉波提供同一光学延时线；A scanning unit 3, the low-coherence reference light and the high-coherence measurement light both pass through the scanning unit 3, and the scanning unit 3 is used to provide the same optical delay for the low-coherence interference wave and the high-coherence interference wave Timeline;
量程倍增单元4，所述量程倍增单元4用于采集所述低相干测量单元1产生的所述低相干干涉波以及扩大测量量程的范围；A range multiplication unit 4, the range multiplication unit 4 is used to collect the low-coherence interference wave generated by the low-coherence measurement unit 1 and expand the range of the measurement range;
信号处理单元5，所述信号处理单元5用于以所述高相干干涉波为参考基准，对量程倍增单元4采集到的所述低相干干涉波进行分析处理，得到被测光学系统106各介质分界面之间的轴向距离；A signal processing unit 5, the signal processing unit 5 is used to analyze and process the low-coherence interference wave collected by the range multiplication unit 4 with the high-coherence interference wave as a reference, and obtain the medium of the measured optical system 106 Axial distance between interfaces;
所述低相干测量单元1与所述量程倍增单元4相连接，所述信号处理单元5分别与所述量程倍增单元4、所述高相干标尺单元2相连接。The low-coherence measurement unit 1 is connected to the range multiplication unit 4 , and the signal processing unit 5 is connected to the range multiplication unit 4 and the high-coherence scale unit 2 respectively.
所述低相干测量单元1还包括第一耦合器102、第一偏振控制器103、第一光环形器104、第一准直器105、第二偏振控制器107、第二光环形器108、波分复用器109、第二准直器110；The low-coherence measurement unit 1 further includes a first coupler 102, a first polarization controller 103, a first optical circulator 104, a first collimator 105, a second polarization controller 107, a second optical circulator 108, wavelength division multiplexer 109, second collimator 110;
所述低相干测量光经由第一偏振控制器103、第一光环形器104、第一准直105器后依次入射到被测光学系统106的各介质分界面上，经各介质分界面反射后依次经过所述第一光环形器104、所述第一光纤分路器401，到达所述量程倍增单元4；所述低相干测量光经过所述第一光纤分路器401后得到的多路低相干测量光；The low-coherence measurement light is sequentially incident on each medium interface of the measured optical system 106 via the first polarization controller 103, the first optical circulator 104, and the first collimator 105, and is reflected by each medium interface. After passing through the first optical circulator 104 and the first optical fiber splitter 401 in sequence, it reaches the range multiplication unit 4; low coherence measurement light;
所述低相干参考光经由第二偏振控制器107、第二光环形器108、波分复用器109、第二准直器110、所述扫描单元3的扫描镜301，垂直入射到所述扫描单元3的反射镜302，经所述扫描单元3的反射镜302反射后返回到达所述第二光环形器108，经所述第二光环形器108、第二光纤分路器402到达所述量程倍增单元4；所述低相干参考光经过所述第二光纤分路器402后得到的多路低相干参考光，相邻光路中的低相干参考光的光程成等差数列；The low-coherent reference light is vertically incident on the The reflection mirror 302 of the scanning unit 3 returns to the second optical circulator 108 after being reflected by the reflection mirror 302 of the scanning unit 3, and reaches the second optical circulator 108 and the second optical fiber splitter 402 to reach the The range multiplication unit 4; the multi-channel low-coherence reference light obtained after the low-coherence reference light passes through the second fiber splitter 402, and the optical paths of the low-coherence reference light in adjacent optical paths form an arithmetic sequence;
所述量程倍增单元4包括多个耦合器403、406、409、412、与各所述耦合器一一对应的探测器对，耦合器403对应探测器404、探测器405，耦合器406对应探测器407、探测器408，耦合器409对应探测器410、探测器411，耦合器412对应探测器413、探测器414，所述低相干测量光经过所述第一光纤分路器401后得到的多路低相干测量光与所述低相干参考光经过所述第二光纤分路器402后得到的多路低相干参考光在所述量程倍增单元的所述耦合器处分别一一对应发生干涉，得到所述低相干干涉波；所述探测器对对所述耦合器输出的所述低相干干涉波进行探测，所述低相干干涉波包括低相干反射干涉波和低相干透射干涉波。The range multiplication unit 4 includes a plurality of couplers 403, 406, 409, 412, and a pair of detectors corresponding to each of the couplers, the coupler 403 corresponds to the detector 404, the detector 405, and the coupler 406 corresponds to the detection 407, detector 408, coupler 409 corresponds to detector 410, detector 411, coupler 412 corresponds to detector 413, detector 414, the low coherence measurement light is obtained after passing through the first optical fiber splitter 401 The multi-channel low-coherence measurement light and the multiple low-coherence reference light obtained after passing through the second optical fiber splitter 402 interfere one-to-one at the couplers of the range multiplication unit. , to obtain the low-coherence interference wave; the detector detects the low-coherence interference wave output by the coupler, and the low-coherence interference wave includes a low-coherence reflection interference wave and a low-coherence transmission interference wave.
所述探测器对包括两个探测器，两个所述探测器分别用于对所述低相干反射干涉波和所述低相干透射干涉波进行探测。两个所述探测器接收到的信号位相相差180°。The detector pair includes two detectors, and the two detectors are respectively used to detect the low-coherence reflection interference wave and the low-coherence transmission interference wave. The signals received by the two detectors have a phase difference of 180°.
所述高相干标尺单元2包括高相干光源201、第三耦合器、第四耦合器、第四耦合器、第三光环形器、第四光环形器和端面镀反射膜的光纤；The high-coherence scale unit 2 includes a high-coherence light source 201, a third coupler, a fourth coupler, a fourth coupler, a third optical circulator, a fourth optical circulator, and an optical fiber coated with a reflective film;
所述高相干光源201发出的光经过所述第三耦合器202后分成高相干参考光和高相干测量光，所述高相干参考光经由所述第三光环形器203、端面镀反射膜的光纤204、所述第三光环形器203后到达所述第四耦合器205，所述高相干测量光经由第四光环形器206、波分复用器109、第二准直器110、所述扫描单元3的扫描镜301、垂直入射到所述扫描单元3的反射镜302，经扫描单元3的反射镜302反射后原路返回到达所述第四光环形器206，经所述第四光环形器206后到达所述第四耦合器205；The light emitted by the high-coherence light source 201 passes through the third coupler 202 and is divided into high-coherence reference light and high-coherence measurement light. After the optical fiber 204 and the third optical circulator 203 reach the fourth coupler 205, the highly coherent measurement light passes through the fourth optical circulator 206, the wavelength division multiplexer 109, the second collimator 110, the The scanning mirror 301 of the scanning unit 3 and the reflecting mirror 302 perpendicularly incident on the scanning unit 3, after being reflected by the reflecting mirror 302 of the scanning unit 3, return to the fourth optical circulator 206 in the same way, and pass through the fourth optical circulator 206. After the optical circulator 206 reaches the fourth coupler 205;
入射到所述第四耦合器205的所述高相干参考光和高相干测量光发生干涉，得到高相干干涉波，所述高相干干涉波包括高相干反射干涉波和高相干透射干涉波。The highly coherent reference light incident on the fourth coupler 205 interferes with the highly coherent measurement light to obtain highly coherent interference waves, and the highly coherent interference waves include highly coherent reflection interference waves and highly coherent transmission interference waves.
所述高相干标尺单元2还包括两个探测器207、208，两个所述探测器分别用于对所述第四耦合器205输出的所述高相干反射干涉波和所述高相干透射干涉波进行探测高相干干涉波的透射波和反射波进行探测。两个所述探测器接收到的信号位相相差180°。The high-coherence scale unit 2 also includes two detectors 207 and 208, and the two detectors are respectively used to detect the high-coherence reflection interference wave and the high-coherence transmission interference wave output by the fourth coupler 205. The wave is detected by the transmitted wave and the reflected wave of the highly coherent interference wave. The signals received by the two detectors have a phase difference of 180°.
各光学器件之间的均采用光纤或光纤器件相连接。All optical devices are connected by optical fibers or optical fiber devices.
本发明还提供了一种光学系统轴向参数测量方法，所述方法应用于本发明提供的光学系统轴向参数测量装置，如图8所示，该方法包括：The present invention also provides a method for measuring an axial parameter of an optical system, the method is applied to the device for measuring an axial parameter of an optical system provided by the present invention, as shown in FIG. 8 , the method includes:
步骤801：闭合光学系统轴向参数测量装置的总电源，点亮高相干光源、低相干光源；Step 801: Turn off the total power supply of the axial parameter measuring device of the optical system, and turn on the high-coherence light source and the low-coherence light source;
步骤802：前后移动被测光学系统，当被测光学系统第一个介质分界面的干涉峰出现在量程倍频单元中的第一组探测器上时，固定被测光学系统；Step 802: moving the optical system under test back and forth, and fixing the optical system under test when the interference peak of the first medium interface of the optical system under test appears on the first group of detectors in the range frequency doubling unit;
步骤803：量程倍增单元中各组探测器接收被测光学系统各分界面处的低相干干涉信号；Step 803: Each group of detectors in the range doubling unit receives low-coherence interference signals at each interface of the measured optical system;
步骤804：信号处理单元采用微分过零法提取所述低相干干涉信号的极大值点，获取被测光学系统各分界面位置信息，并根据信号处理单元显示的干涉波图形，以高相干标尺单元产生的高相干干涉波为参考计算被测光学系统各分界面之间的距离，所述干涉波图形包括低相干干涉波图形和高相干干涉波图形。Step 804: The signal processing unit uses the differential zero-crossing method to extract the maximum point of the low-coherence interference signal, obtains the position information of each interface of the optical system under test, and uses the high-coherence scale according to the interference wave pattern displayed by the signal processing unit The high-coherence interference wave generated by the unit is used as a reference to calculate the distance between the interfaces of the measured optical system, and the interference wave pattern includes a low-coherence interference wave pattern and a high-coherence interference wave pattern.
其中，步骤804具体包括：Wherein, step 804 specifically includes:
当相邻两个介质分界面对应的低相干干涉信号处在同一个探测器上时，如图4所示，利用公式计算相邻两个介质分界面的轴向距离，其中，d为相邻两个介质分界面的轴向距离；n为干涉波图形中相邻两个介质分界面对应的低相干干涉信号的最大值之间包含高相干干涉信号周期的个数，λ为高相干光源发出光的波长；When the low-coherence interference signals corresponding to two adjacent medium interfaces are on the same detector, as shown in Figure 4, using the formula Calculate the axial distance between two adjacent medium interfaces, where d is the axial distance between two adjacent medium interfaces; n is the maximum value of the low-coherence interference signal corresponding to two adjacent medium interfaces in the interference wave pattern The values include the number of high-coherence interference signal cycles, and λ is the wavelength of light emitted by the high-coherence light source;
当相邻两个介质分界面对应的低相干干涉信号不在同一个探测器上时，如图5、6所示，利用公式计算相邻两个介质分界面的轴向距离，其中，d为相邻两个介质分界面的轴向距离；nm为干涉波图形中前一介质分界面对应的低相干干涉信号的最大值与高相干干涉信号起始值之间包含高相干涉信号周期的个数；nn为干涉波图形中后一介质分界面对应的低相干干涉信号的最大值与高相干涉信号起始值之间包含高相干干涉信号周期的个数；Lm、Ln分别为前一介质分界面和后一介质分界面所对应的低相干参考光路的光程；λ为高相干光源发出光的波长。When the low-coherence interference signals corresponding to two adjacent medium interfaces are not on the same detector, as shown in Figures 5 and 6, use the formula Calculate the axial distance between two adjacent medium interfaces, where d is the axial distance between two adjacent medium interfaces; n m is the maximum value of the low-coherence interference signal corresponding to the previous medium interface in the interference wave pattern The number of cycles of the high-phase interference signal included between the initial value of the high-coherence interference signal; n n is the difference between the maximum value of the low-coherence interference signal corresponding to the latter medium interface in the interference wave pattern and the initial value of the high-phase interference signal The interval includes the number of high-coherence interference signal periods; L m and L n are the optical paths of the low-coherence reference optical paths corresponding to the previous medium interface and the latter medium interface respectively; λ is the wavelength of light emitted by the high-coherence light source.
本发明提供的测量光学系统轴向参数的装置及方法，设置了低相干测量单元、高相干标尺单元、扫描单元、量程倍增单元和信号处理单元，所述低相干测量单元用于产生低相干干涉波，所述高相干标尺单元用于产生高相干干涉波，所述低相干参考光和所述高相干测量光均经过所述扫描单元，使所述低相干干涉波和所述高相干干涉波提供同一光学延时线，通过设置所述量程倍增单元增加了装置的测量范围，信号处理单元，所述信号处理单元用于以所述高相干干涉波为参考基准，对量程倍增单元采集到的所述低相干干涉波进行分析处理，得到光学系统各介质分界面之间的轴向距离，此外，本发明提供的装置中采用的探测器为差分探测器，提高了测量信号的信噪比，能够实现对信号准确的测量。The device and method for measuring the axial parameters of the optical system provided by the present invention are provided with a low-coherence measurement unit, a high-coherence scale unit, a scanning unit, a range multiplication unit and a signal processing unit, and the low-coherence measurement unit is used to generate low-coherence interference The high-coherence scale unit is used to generate high-coherence interference waves, the low-coherence reference light and the high-coherence measurement light both pass through the scanning unit, so that the low-coherence interference waves and the high-coherence interference waves The same optical delay line is provided, and the measurement range of the device is increased by setting the range multiplication unit, and the signal processing unit is used to use the high coherence interference wave as a reference standard to collect the range multiplication unit The low-coherence interference wave is analyzed and processed to obtain the axial distance between the medium interfaces of the optical system. In addition, the detector used in the device provided by the invention is a differential detector, which improves the signal-to-noise ratio of the measurement signal. Accurate measurement of the signal can be realized.
作为本发明的又一实施例，本发明提供的光学系统轴向参数测量装置，由低相干光源、高相干光源、7个耦合器、4个光环行器、1个波分复用器、2个准直器、2个偏振控制器、1个反射镜、9个探测器、1个一维平移台、1个中空直角扫描镜，2个光纤分束器、信号及数据处理单元组成。本测量装置包含两个马赫一泽德型光纤干涉仪(高相干标尺单元和低相干测量单元)，其中一个光纤干涉仪(低相干测量单元)感应被测光学系统分界面位置，另一个光纤干涉仪(高相干标尺单元)用于解调相邻两分界面之间距离值。利用共用的扫描单元，使系统的低相干干涉和高相干干涉状态协同一致。As another embodiment of the present invention, the optical system axial parameter measurement device provided by the present invention consists of a low-coherence light source, a high-coherence light source, 7 couplers, 4 optical circulators, 1 wavelength division multiplexer, 2 It consists of a collimator, 2 polarization controllers, 1 mirror, 9 detectors, 1 one-dimensional translation stage, 1 hollow right-angle scanning mirror, 2 optical fiber beam splitters, and signal and data processing unit. The measurement device includes two Mach-Zehnder fiber optic interferometers (high coherence scale unit and low coherence measurement unit), one of which is a fiber optic interferometer (low coherence measurement unit) to sense the position of the interface of the optical system under test, and the other optical fiber interferometer The instrument (high coherence scale unit) is used to demodulate the distance value between two adjacent interfaces. By using a common scanning unit, the low-coherence interference and high-coherence interference states of the system are coordinated.
高相干光源201发出的光经过第三耦合器202后分被分成两路光，一路光经由第三光环形器203、端面镀反射膜的光纤204、第三光环形器203后到达第四耦合器205，另一路光经由第四光环形器206、波分复用器109、第二准直器110、扫描镜301、垂直如射到反射镜302，经反射镜302反射后原路返回到达第四光环形器206，经第四光环形器206后到达第四耦合器205，两路光在第四耦合器205处相遇，并发生干涉，干涉信号由探测器207、探测器208接收(探测器207、探测器208接收到的干涉信号相位相差180°)，此干涉信号可表示为:The light emitted by the high-coherence light source 201 passes through the third coupler 202 and is divided into two paths of light. One path of light passes through the third optical circulator 203, the optical fiber 204 coated with a reflective film on the end surface, and the third optical circulator 203 to reach the fourth coupling 205, another path of light passes through the fourth optical circulator 206, the wavelength division multiplexer 109, the second collimator 110, the scanning mirror 301, vertically shoots to the reflector 302, and returns to the original path after being reflected by the reflector 302. The fourth optical circulator 206 reaches the fourth coupler 205 after passing through the fourth optical circulator 206, and the two paths of light meet at the fourth coupler 205 and interfere, and the interference signal is received by the detector 207 and the detector 208 ( Detector 207, the interference signal phase difference that detector 208 receives is 180 °), this interference signal can be expressed as:
I1＝I0(1+Mcos(K1ΔZ)) (1)I 1 ＝I 0 (1+Mcos(K 1 ΔZ)) (1)
式中，I0为高相干干涉信号的直流分量，M为干涉条纹的可见度，K1为高相干光源发出光的波数，ΔZ为高相干参考光路与高相干测量光路的光程差。干涉信号的波形如图2所示。In the formula, I 0 is the DC component of the high-coherence interference signal, M is the visibility of the interference fringes, K 1 is the wave number of the light emitted by the high-coherence light source, and ΔZ is the optical path difference between the high-coherence reference optical path and the high-coherence measurement optical path. The waveform of the interference signal is shown in Figure 2.
低相干光源101发出的光经过第一耦合器102后分被分成两路光，一路经由第一偏振控制器103、第一光环形器104、第一准直器105后依次入射到被测光学系统106各介质分界面上，经各介质分界面反射后到达第一光环形器104，经第一光环形器104、第一光纤分路器401依次到达耦合器403、耦合器406、耦合器409、耦合器412中，另一路光经由第二偏振控制器107、第二光环形器108、波分复用器109、第二准直器110、扫描镜301，垂直如射到反射镜302，经反射镜302反射后原路返回到达第二光环形器108，经第二光环形器108、光纤分路器402依次到达耦合器403、耦合器406、耦合器409、耦合器412中，两路光在耦合器403、耦合器406、耦合器409、耦合器412处相遇，并发生干涉，干涉信号由探测器404、探测器405、探测器407、探测器408、探测器410、探测器411、探测器413、探测器414接收(每对探测器接收到的干涉信号相位相差180°)，当两路光的光程差小于低相干光源的相干长度时，探测器接收到的是低相干干涉信号，此信号可表示为:The light emitted by the low-coherence light source 101 passes through the first coupler 102 and is divided into two paths of light, and one path passes through the first polarization controller 103, the first optical circulator 104, and the first collimator 105, and then enters the optical fiber under test in sequence. On each medium interface of the system 106, it reaches the first optical circulator 104 after being reflected by each medium interface, and then reaches the coupler 403, the coupler 406, and the coupler through the first optical circulator 104 and the first fiber splitter 401 in sequence 409. In the coupler 412, another path of light passes through the second polarization controller 107, the second optical circulator 108, the wavelength division multiplexer 109, the second collimator 110, and the scanning mirror 301, and then vertically hits the mirror 302 After being reflected by the reflector 302, the original path returns to the second optical circulator 108, and then arrives at the coupler 403, the coupler 406, the coupler 409, and the coupler 412 through the second optical circulator 108 and the fiber splitter 402 in sequence, The two paths of light meet at the coupler 403, coupler 406, coupler 409, and coupler 412, and interfere. The interference signal is detected by the detector 404, detector 405, detector 407, detector 408, detector 410, and detector 411, detector 413, and detector 414 receive (the phase difference of the interference signal received by each pair of detectors is 180°), when the optical path difference of the two paths of light is less than the coherence length of the low-coherence light source, what the detector receives is Low coherence interference signal, this signal can be expressed as:
式中，I00为低相干干涉信号的直流分量，Lc为干涉长度，k为低相干光源发出光的波数，Δz为低相干测量光路与低相干参考光路的光程差。从(2)式可知，Δz的变化可同时引起干涉条纹可见度及干涉信号相位变化。当Δz＝0时，I2将取最大值，干涉波形如图3所示。In the formula, I 00 is the DC component of the low-coherence interference signal, L c is the interference length, k is the wavenumber of the light emitted by the low-coherence light source, and Δz is the optical path difference between the low-coherence measurement optical path and the low-coherence reference optical path. It can be known from formula (2) that the change of Δz can simultaneously cause the change of the visibility of the interference fringe and the phase of the interference signal. When Δz = 0, I 2 will take the maximum value, and the interference waveform is shown in Figure 3.
当相邻两个介质分界面位置干涉信号处在同一个探测器上时，如图4所示，两个介质分界面的轴向距离为：When the position interference signals of two adjacent media interfaces are on the same detector, as shown in Figure 4, the axial distance between the two media interfaces is:
式中：d-为两个介质分界面的轴向距离；In the formula: d- is the axial distance between the two medium interfaces;
n-两个介质分界面位置干涉信号的最大值中包含高相干标尺单元干涉信号周期的个数；n-the maximum value of the interference signal at the two medium interface positions contains the number of periods of the interference signal of the high-coherence scale unit;
λ-为高相干光源发出光的波长。λ- is the wavelength of light emitted by the highly coherent light source.
当相邻两个介质分界面位置干涉信号不处在同一个探测器上时，如图5、图6所示，两个介质分界面的轴向距离为：When the position interference signals of two adjacent media interfaces are not on the same detector, as shown in Figure 5 and Figure 6, the axial distance between the two media interfaces is:
式中：d-为两个介质分界面的轴向距离；In the formula: d- is the axial distance between the two medium interfaces;
nm-为前一介质分界面位置干涉信号的最大值与高相干标尺单元干涉信号起始值之间包含高相干标尺单元干涉信号周期的个数，如图5所示；n m - is the number of high-coherence scale unit interference signal cycles between the maximum value of the previous medium interface position interference signal and the initial value of the high-coherence scale unit interference signal, as shown in Figure 5;
nn-为后一介质分界面位置干涉信号的最大值与高相干标尺单元干涉信号起始值之间包含高相干标尺单元干涉信号周期的个数，如图6所示；n n - is the number of high-coherence scale unit interference signal cycles between the maximum value of the latter medium interface position interference signal and the initial value of the high-coherence scale unit interference signal, as shown in Figure 6;
Lm Ln-为分别与探测器相对应的低相干参考光路的光程；L m L n - is the optical path of the low-coherence reference optical path corresponding to the detector;
λ-为高相干光源发出光的波长。λ- is the wavelength of light emitted by the highly coherent light source.
等差光纤光程差的标定：Calibration of the optical path difference of the arithmetic fiber:
量程倍增单元中等差光纤光程差设计值为高相干光源的相干长度，扫描镜的扫描导轨的长度略大于高相干光源的相干长度，测量原理如图7所示。The design value of the optical path difference of the differential optical fiber in the range doubling unit is the coherence length of the high-coherence light source, and the length of the scanning guide rail of the scanning mirror is slightly larger than the coherence length of the high-coherence light source. The measurement principle is shown in Figure 7.
ΔLn+2-ΔLn+1＝ΔLn+1-ΔLn1＝S (5)ΔL n+2 - ΔL n+1 = ΔL n+1 - ΔL n1 = S (5)
式中：S为高相干光源的相干长度，导轨的扫描长度为S'>S。In the formula: S is the coherence length of the highly coherent light source, and the scanning length of the guide rail is S'>S.
所以当被测物体处于下列位置时:So when the measured object is in the following positions:
ΔLn+S＜L＜ΔLn+S′ (6)ΔL n +S<L<ΔL n +S' (6)
在扫描镜的整个移动过程中，首先是对应第n+1组光纤组出现干涉条纹，During the whole moving process of the scanning mirror, firstly, interference fringes appear corresponding to the n+1th fiber group,
继续移动，对应第n组光纤组也出现干涉条纹。Continue to move, and interference fringes also appear corresponding to the nth group of optical fiber groups.
设这两个时刻位置干涉信号的最大值与高相干标尺单元干涉信号起始值的距离分别是Sn+1和Sn，则有:Assuming that the distances between the maximum value of the position interference signal at these two moments and the initial value of the interference signal of the highly coherent scale unit are S n+1 and S n , then:
ΔLn+1＝ΔLn+2(Sn-Sn+1) (7)ΔL n+1 ＝ΔL n +2(S n -S n+1 ) (7)
公式(7)可由第n组光纤组长度求取第n+1组光纤组长度，第一组光纤组可以通过低相干定位干涉信号与高相干标尺单元干涉信号直接得到。Formula (7) can be used to obtain the length of the n+1th group of fiber groups from the length of the nth group of fiber groups, and the first group of fiber groups can be directly obtained through the low-coherence positioning interference signal and the high-coherence scale unit interference signal.
本发明提供的测量光学系统轴向参数的装置及方法，设置了低相干测量单元、高相干标尺单元、扫描单元、量程倍增单元和信号处理单元，所述低相干测量单元用于产生低相干干涉波，所述高相干标尺单元用于产生高相干干涉波，所述低相干参考光和所述高相干测量光均经过所述扫描单元，使所述低相干干涉波和所述高相干干涉波提供同一光学延时线，通过设置所述量程倍增单元增加了装置的测量范围，信号处理单元，所述信号处理单元用于以所述高相干干涉波为参考基准，对量程倍增单元采集到的所述低相干干涉波进行分析处理，得到光学系统各介质分界面之间的轴向距离，此外，本发明提供的装置中采用的探测器为差分探测器，提高了测量信号的信噪比，能够实现对信号准确的测量。The device and method for measuring the axial parameters of the optical system provided by the present invention are provided with a low-coherence measurement unit, a high-coherence scale unit, a scanning unit, a range multiplication unit and a signal processing unit, and the low-coherence measurement unit is used to generate low-coherence interference The high-coherence scale unit is used to generate high-coherence interference waves, the low-coherence reference light and the high-coherence measurement light both pass through the scanning unit, so that the low-coherence interference waves and the high-coherence interference waves The same optical delay line is provided, and the measurement range of the device is increased by setting the range multiplication unit, and the signal processing unit is used to use the high coherence interference wave as a reference standard to collect the range multiplication unit The low-coherence interference wave is analyzed and processed to obtain the axial distance between the medium interfaces of the optical system. In addition, the detector used in the device provided by the invention is a differential detector, which improves the signal-to-noise ratio of the measurement signal. Accurate measurement of the signal can be realized.
本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分互相参见即可。Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.
本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想；同时，对于本领域的一般技术人员，依据本发明的思想，在具体实施方式及应用范围上均会有改变之处。综上所述，本说明书内容不应理解为对本发明的限制。In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, there will be changes in specific implementation methods and application ranges. In summary, the contents of this specification should not be construed as limiting the present invention.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108398098A (en) * | 2018-05-11 | 2018-08-14 | 中国科学院苏州生物医学工程技术研究所 | A kind of optical surface spacing non-contact measurement apparatus and method |
| CN111504176A (en) * | 2020-04-30 | 2020-08-07 | 浙江大学 | Large optical path closed-loop measurement system based on two-stage actuator structure |
| CN112649956A (en) * | 2020-12-18 | 2021-04-13 | 西北大学 | Optical fiber phase scanning tuning device and method for calibrating deviation in real time |
| CN117678968A (en) * | 2023-12-25 | 2024-03-12 | 上海雄博精密仪器股份有限公司 | An AI-based diopter detection method, system, equipment and storage medium |
| CN118111681A (en) * | 2024-04-28 | 2024-05-31 | 广东工业大学 | A low-cost and high-precision optical lens group parameter measurement method and system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5633716A (en) * | 1995-12-18 | 1997-05-27 | General Electric Company | Self-aligning retroreflector target carrier |
| CN1201901A (en) * | 1998-03-20 | 1998-12-16 | 清华大学 | Wave-length scanning and interfering system and signal process method therefor |
| US6064630A (en) * | 1997-06-06 | 2000-05-16 | Litton Systems, Inc. | Sensor with an optical interferometric pick-off |
| CN101680782A (en) * | 2008-02-29 | 2010-03-24 | 株式会社藤仓 | Physical quantity measuring device of optical frequency domain reflectometry system and temperature and strain measuring method using the same |
-
2017
- 2017-10-16 CN CN201710959724.2A patent/CN107764197B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5633716A (en) * | 1995-12-18 | 1997-05-27 | General Electric Company | Self-aligning retroreflector target carrier |
| US6064630A (en) * | 1997-06-06 | 2000-05-16 | Litton Systems, Inc. | Sensor with an optical interferometric pick-off |
| CN1201901A (en) * | 1998-03-20 | 1998-12-16 | 清华大学 | Wave-length scanning and interfering system and signal process method therefor |
| CN101680782A (en) * | 2008-02-29 | 2010-03-24 | 株式会社藤仓 | Physical quantity measuring device of optical frequency domain reflectometry system and temperature and strain measuring method using the same |
Non-Patent Citations (2)
| Title |
|---|
| 李昭莹: "基于复合干涉的光纤低相干干涉传感系统研究", 《光学学报》 * |
| 马森等: "光纤双干涉在线绝对测量技术研究", 《仪器仪表学报》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108398098A (en) * | 2018-05-11 | 2018-08-14 | 中国科学院苏州生物医学工程技术研究所 | A kind of optical surface spacing non-contact measurement apparatus and method |
| CN111504176A (en) * | 2020-04-30 | 2020-08-07 | 浙江大学 | Large optical path closed-loop measurement system based on two-stage actuator structure |
| CN111504176B (en) * | 2020-04-30 | 2021-03-30 | 浙江大学 | A large optical path closed-loop measurement system based on two-stage actuator structure |
| CN112649956A (en) * | 2020-12-18 | 2021-04-13 | 西北大学 | Optical fiber phase scanning tuning device and method for calibrating deviation in real time |
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