CN102231472A - Laser pulse synchronization control device - Google Patents

Abstract

The invention discloses a laser pulse synchronization control device which is connected with M paths of laser pulse sources, wherein M is a natural number larger than 1. The laser pulse synchronization control device is characterized in that: except one path, each of other paths of the laser pulse source sequentially comprises a spectroscope, a static light delayer and a dynamic light delaying module, and the one path of the laser pulse source sequentially comprises a spectroscope and a static light delayer; laser pulse sub-beams of the spectroscope of each path are input to each photo detector, and outputs of the photo detectors are connected with a delay controller; and the delay controller controls and is connected with each dynamic light delaying module. The laser pulse synchronization control device breaks through a traditional synchronization method for controlling the current electro-optical Q-switching trigger time by utilizing the feedback of previous pulse period data, and carries out fast signal processing and delay time modification by utilizing static light delay and detecting current pulse, thus pulse synchronization accuracy can be further improved, and more application requirements are met.

Description

A laser pulse synchronization control device

technical field

The invention relates to the field of optoelectronic technology, in particular to a laser pulse synchronization control device capable of improving synchronization accuracy.

Background technique

High-energy, high-peak-power lasers have important and extensive applications in the fields of laser processing, laser nonlinear effects, and remote sensing. Q-switching the laser is the main way to obtain high energy and high peak power output. In order to meet the application requirements, the methods to further increase the energy and peak power mainly include: increasing the pump injection, multi-stage cascade amplification and synchronous synthesis of multiple lasers. Due to the limitation of laser thermal effect, when the pump injection increases to a certain extent, the laser output energy and power will be saturated. Compared with cascaded amplification, multiple laser synchronous synthesis has the advantages of simple unit technology, good thermal management, good laser transmission characteristics, good system scalability and flexible configuration, and has broad and important development and application prospects. The key technology in synchronous synthesis of multiple lasers is the synchronization of laser pulses, that is, the precise overlapping of two or more laser pulses in time.

The Q-switched laser pulse width is usually on the order of ns or tens of ns. The traditional laser pulse synchronization method is realized by controlling the triggering moment of Q-switching. First, sample the laser output pulses of each channel, determine the relative time difference generated by each laser pulse, analyze and process the time difference signal, and feedback control the electro-optic Q-switching trigger time of the next pulse cycle of each laser, so that the laser pulses are output synchronously . Using this method, the pulse synchronization accuracy can reach ±1ns , pp. 633-636). However, due to the uncertainty of the delay of the laser output relative to the Q-switching trigger signal, that is, the uncertainty of the laser pulse establishment time, this feedback controls the laser at the electro-optic Q-switching trigger moment of the next pulse cycle of each laser. The accuracy of the pulse synchronization method is difficult to further improve.

Contents of the invention

The problem to be solved by the present invention is: how to provide a laser pulse synchronization control device, which can overcome the defects of the current laser pulse synchronization method of the electro-optic Q-switching triggering time for feedback control of the next pulse period of each laser, and further improve the laser pulse synchronization. precision.

The technical problem proposed by the present invention is solved in this way: provide a kind of laser pulse synchronous control device, connect M road laser pulse source, M is the natural number greater than 1, it is characterized in that: except one road other laser pulses from input to The output includes setting a beam splitter, a static light delayer and a dynamic light delay module in turn, and the one path from input to output includes setting a beam splitter and a static light delayer in turn; The beams are input to respective photodetectors, and the outputs of the photodetectors are all connected to a delay controller; the delay controller is connected to each of the dynamic optical delay modules.

According to the laser pulse synchronization control device provided by the present invention, M=2.

According to the laser pulse synchronization control device provided by the present invention, 3≤M<1000.

According to the laser pulse synchronization control device provided by the present invention, the dynamic optical delay module includes an electro-optic driver and N dynamic optical delay units connected thereto, where N is a natural number between 3 and 100; each dynamic optical delay The units all include an electro-optic polarization modulator and four polarization beam splitters connected by control thereof; two of the four polarization beam splitters are located on the same line as the input light pulse, and the other two are located on the parallel line to the input light pulse.

The beneficial effects of the present invention are as follows: 1. The traditional pulse synchronization method corrects the delay time of the Q-switching trigger electrical signal by measuring the time difference of the optical pulse in the emitted pulse cycle, so that the synchronization accuracy is approximately equal to the jitter of the optical pulse establishment time; 2. The invention proposes to further improve the pulse synchronization precision by detecting the time difference of two beams of light pulses in the current pulse period, and performing fast signal processing and delay time correction.

Description of drawings

Fig. 1 is a schematic structural view of a first embodiment of a laser pulse synchronization control device that improves synchronization accuracy provided by the present invention;

Fig. 2 is a schematic structural diagram of the first dynamic optical delayer in the first embodiment of a laser pulse synchronization control device that improves synchronization accuracy provided by the present invention;

FIG. 3 is a schematic structural diagram of a second embodiment of a laser pulse synchronization control device for improving synchronization accuracy provided by the present invention.

Wherein the reference numerals are: 1-the first beam splitter, 2-the first photodetector, 3-the second beam splitter, 4-the second photodetector, 5-the first static light delay device, 6-the second Static optical delayer, 7-delay controller, 8-the first dynamic optical delayer, 9-the first delay control signal output by the delay controller, 10-the first incident light pulse, 11-the second Incident light pulse, 12-first outgoing light pulse, 13-second outgoing light pulse, 14-time difference between the first and second incident light pulse, 15-electro-optic driver, 16-electro-optic drive signal, 17-first dynamic light The input light pulse of the delay device, 18-the first electro-optic polarization modulator, 19-the second electro-optic polarization modulator, 20-the third electro-optic polarization modulator, 21-the first polarization beam splitter, 22-the second polarization beam splitter , 23-the third polarization beam splitter, 24-the fourth polarization beam splitter, 25-the fifth polarization beam splitter, 26-the sixth polarization beam splitter, 27-the seventh polarization beam splitter, 28-the eighth polarization beam splitter, 29 -the ninth polarization beam splitter, 30-the tenth polarization beam splitter, 31-the eleventh polarization beam splitter, 32-the twelfth polarization beam splitter, 33-the first dynamic light delay unit, 34-the second dynamic light delay Time unit, 35-the third dynamic light delay unit, 36-the output light pulse of the dynamic light delay device, 37-the third incident light pulse, 38-the third beam splitter, 39-the third photodetector, 40- The third static optical delayer, 41-the second dynamic optical delayer, the second delay control signal output by the 42-delay controller, 43-the third outgoing light pulse, 44-the first and the third incident light The time difference of the pulse.

Detailed ways

At first, illustrate the inventive thought:

Detect the time difference between two beams of light pulses in the current pulse period, and perform fast signal processing and delay time correction. One of the keys: the static optical delayer on each optical pulse provides enough time for fast signal processing and delay time correction.

Second, the present invention will be further described below in conjunction with accompanying drawing:

The first embodiment of the laser pulse synchronization controller that improves the synchronization accuracy provided by the present invention has a structure as shown in Figure 1, including: a first beam splitter 1, a second beam splitter 3, a first photodetector 2, a second photoelectric Detector 4, first static optical delayer 5, second static optical delayer 6, delay controller 7, first dynamic optical delayer 8; first incident light pulse 10 is divided by first beam splitter 1 Two beams, one beam is input to the first photodetector 2, the other beam is input to the first static light delay device 5, and then output; the second incident light pulse 11 is divided into two beams by the second beam splitter 3, and one beam is input to the second Photodetector 4, another bundle input second static optical delay device 6, the light pulse that the second static optical delay device 6 outputs is input first dynamic optical delay device 8 again, then output; First photodetector 2 and the output electric signal of the second photodetector 4 are input to the delay controller 7; the first delay control signal 9 output by the delay controller 7 is input to the first dynamic optical delayer 8.

Its working principle is: set the first beam splitter 1 and the second beam splitter 3 at the same distance from the two entrances of the laser pulse synchronization controller, so that the optical signals obtained by sampling are respectively input into the first photodetector 2 and the second beam splitter. Photodetector 4. The output signal is input to the delay controller 7 for fast signal processing, and the first delay control signal 9 is generated and input to the first dynamic optical delayer 8 . The first dynamic optical delayer 8 performs fast optical delay state switching to reach the required optical delay time. At the same time, the first static optical delayer 5 and the second static optical delayer 6 are set in the optical path, and the two optical pulses generate a fixed delay therein, so that the second incident optical pulse 11 arrives at the first dynamic optical delay Before the timer 8, the delay controller 7 and the electro-optic driver 15 have enough time for signal processing. At the same time, the delay values of the static optical delay devices 5 and 6 can be manually adjusted, thus having the function of calibrating the optical path. By changing the delay value of the first dynamic optical delay device 8, the delay value of the second incident light pulse 11 is quickly corrected, so that the light pulses 10 and 11 reach the corresponding exits of the laser pulse synchronization controller at the same time, achieving precise control of the laser pulse purpose of synchronicity.

The first dynamic optical delay device 8, the structure as shown in Figure 2, includes: electro-optic driver 15, the first dynamic optical delay unit 33, the second dynamic optical delay unit 34 to the Nth dynamic optical delay unit 35, wherein N is a positive integer between 3 and 100, where N is 3; the first delay control signal 9 output by the delay controller 7 is input to the electro-optic driver 15, and the output signal 16 of the electro-optic driver 15 is input to the first dynamic light delay unit 33 to the electro-optic polarization modulator 18 to 20 of the third dynamic light delay unit 35; the first dynamic light delay unit 33 includes the first electro-optic polarization modulator 18, the first to the fourth polarization beam splitter 21 to 24, when the first When the driving voltage of an electro-optic polarization modulator 18 is zero, the input light pulse 17 of the unit 33 has a constant polarization direction when passing through the modulator 18, and the light pulse 17 passes through the first and second polarization beam splitters 21 and 22 in sequence After inputting the second dynamic light delay unit 34, when the driving voltage of the first electro-optic polarization modulator 18 is a half-wave voltage, the light pulse is sequentially transmitted by the first, third, fourth and second polarization beam splitters 21, 23, 24 and 22 reflections, and then input the second dynamic light delay unit 34; by analogy, the third dynamic light delay unit 35 includes the third electro-optical polarization modulator 20, the ninth to the twelfth polarization beam splitter 29 to 32, When the driving voltage of the third electro-optic polarization modulator 20 is zero, the input light pulse of the unit 35 has no change in polarization direction when passing through the modulator 20, and the light pulse passes through the ninth and tenth polarization beam splitters 29 and 30 in turn. After the output, when the driving voltage of the third electro-optic polarization modulator 20 is a half-wave voltage, the light pulse is reflected by the ninth, eleventh, twelfth and tenth polarization beam splitters 29, 31, 32 and 30 in turn, and then output.

Its working principle is:

(1) The first driving mode

For the first dynamic optical delay unit 33, when the driving voltage of the electro-optic polarization modulator 18 is respectively zero and half-wave voltage, the relative optical path difference of the light pulse 17 passing through the unit 33 is the first polarization beam splitter 21 The sum of the optical paths from the third polarization beam splitter 23 and the fourth polarization beam splitter 24 to the second polarization beam splitter 22 corresponds to the optical delay difference DL1. The corresponding delay difference DL2 of the second dynamic optical delay unit 34 is twice of DL1, and so on, the delay difference DLN of the Nth dynamic optical delay unit 35 is 2N times of DL1. Therefore, by setting the driving voltage (zero or half-wave voltage) of each electro-optic crystal, a relative delay value from zero to 2N+1 times DL1 can be obtained, and the delay step is DL1. For example, in order to make the laser pulse synchronous controller achieve the delay control accuracy of ±100ps, it is desirable to take DL1 as 100ps, take N as 3, and get a delay range of 0 to 0.7ns, take N as 5, and get a delay range of 0 to 3.2ns delay range.

(2) The second drive mode

The first dynamic optical delayer 8 can also adopt the second driving method, which is different from the above-mentioned driving method in that when the driving voltage of the first electro-optic polarization modulator 18 is zero, the optical pulses are sequentially driven by the first , the third, the fourth and the second polarization beam splitter 21, 23, 24 and 22 reflections, and then input the second dynamic light delay unit 34, when the driving voltage of the first electro-optic polarization modulator 18 is a half-wave voltage, The light pulses pass through the first and second polarizing beam splitters 21 and 22 in turn and then input into the second dynamic light delay unit 34; and so on, when the driving voltage of the Nth electro-optic polarization modulator 20 is zero, the The light pulses are reflected by the 4N-3, 4N-1, 4N and 4N-2 polarizing beam splitters 29, 31, 32 and 30 in turn, and then output, and the driving voltage of the Nth electro-optic polarization modulator 20 is When the voltage is half-wave, the light pulses pass through the 4N-3 and 4N-2 polarizing beam splitters 29 and 30 sequentially and then output.

Fig. 3 is the second embodiment of the laser pulse synchronous controller that improves synchronous precision provided by the present invention, the number of incident light pulse, spectroscopic mirror, photodetector and static light delayer is increased to M, and M is 3 to 1000 A positive integer between them, where M is 3, the output delay control signal of the delay controller 7 and the number of dynamic optical delayers are increased to 2. The 3rd incident light pulse 37 is divided into two beams by the 3rd spectroscopic mirror 38, and one beam is input the 3rd photodetector 39, another beam is input the 3rd static light delay device 40, the light that the 3rd static light delay device 40 outputs Pulse input second dynamic light delay device 41 again, then output; The output electric signal input delay controller 7 of the 3rd photodetector 39; The second delay control signal 42 that delay controller 7 outputs is input second dynamic Optical delayer 41.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.

Claims (4)

1. A laser pulse synchronous control device, connected to M road laser pulse sources, M is a natural number greater than 1, characterized in that: except one road, other laser pulses include setting a beam splitter and static light delay from input to output in sequence device and a dynamic optical delay module, said one path from input to output then sequentially includes a spectroscope and a static optical delay device; the laser pulse beam splitting of the spectroscope in each path is input to a respective photodetector, and the photodetector The outputs of all the devices are connected to a delay controller (7); the delay controller (7) controls and connects each of the dynamic optical delay modules. 2. The laser pulse synchronization control device according to claim 1, characterized in that: M=2. 3. The laser pulse synchronization control device according to claim 1, characterized in that: 3≤M<1000. 4. The laser pulse synchronization control device according to claim 1, characterized in that: the dynamic optical delay module comprises an electro-optical driver (15) and N dynamic optical delay units connected thereto, and N is between 3 and 100 natural number between; each dynamic light delay unit all comprises electro-optic polarization modulator (18) and four polarizing beam splitters connected by its control; two of said four polarizing beam splitters are located on the same straight line of the input light pulse, and the other Two are located on a straight line parallel to the input light pulse.

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