WO2021114034A1 - Ultra-high-speed optical parametric amplification optical imaging system - Google Patents

Abstract

An ultra-high-speed optical parametric amplification optical imaging system, comprising a light source system (101), a light splitting delay system (201), an optical parametric amplification system (301), and an image recording system (401). Beam splitting and delay processing are performed on incident continuous or long pulse laser to obtain a plurality of sub-beams carrying object information having specific time delays; non-collinear optical parametric amplification is performed on the sub-beams by taking incident ultrashort pulse laser as a pump to obtain idler frequency light arrays carrying the object information having the specific time delays; the object information having the specific time delays carried by the incident idler frequency light arrays is imaged. An object is imaged at different time points, framing imaging having a high spatial bandwidth product, a high framing frequency, and more than ten frames is achieved, and ultra-high-speed optical imaging having picosecond and even femtosecond time resolution is achieved.

Description

An ultra-high-speed optical parametric amplification optical imaging system Technical field

The invention relates to the field of optical imaging, in particular to an ultra-high-speed optical parametric amplification optical imaging system with a time resolution of picoseconds or even femtoseconds.

Background technique

High-speed optical imaging technology has important applications in many fields, such as extreme speed flyer technology, Z-Pinch magnetic pinch and variable specific impulse magnetic plasma rocket and other extreme conditions of scientific research. In the fields of ignition, laser plasma, and femtosecond chemistry, ultrafast processes are often on the time scale of picoseconds or even femtoseconds. Recording these transient optical processes requires time spans on the order of tens of picoseconds, femtosecond time resolution, and terahertz. In the existing technology, the main photography frequency of the rotating mirror high-speed imaging technology is in the range of 10 ⁶ fps to 10 ⁷ fps (frame per second), combined with optical acceleration, network photography and other technologies, it can only reach 10 ⁹ fps (frames per second); the variable tube technology has the advantages of wavelength conversion and low-light imaging, but its imaging spatial bandwidth product and the number of frames are limited by the electronic optical imaging system and the electronic deflection system itself, supplemented by Image decomposition technology can increase the photography frequency to 10 ⁹ fps; with the rapid development of ultra-short pulse laser technology, the ultra-fast holographic imaging technology with femtosecond time resolution has been developed rapidly, and the ultra-short pulse holographic technology with amplitude splitting and azimuth encoding has been developed rapidly. Realize ultra-high-speed imaging with a framing time of 0.3 picoseconds. The ultra-fast holographic technology using wavefront splitting and azimuth encoding has also successfully obtained 4 picosecond-level framing intervals of water and CS ₂ nonlinear change process images; In addition, wavelength coding and polarization coding technologies have also appeared, but these technologies are difficult to obtain more than ten high-time-resolved optical images. Therefore, for picosecond-level extremely high-speed optical imaging, high time resolution, high spatial bandwidth product, and high resolution Amplitude frequency and the number of high-quantity image shooting are both crucial technical parameters; although ultra-fast optical technology can obtain high-time-resolved optical images, if you still need to meet high spatial bandwidth product, high framing frequency and more than ten Multi-frame imaging still faces huge technical challenges.

technical problem

The main purpose of the present invention is to provide an ultra-high-speed optical parametric magnification optical imaging system, which aims to solve the technical problem that the spatial bandwidth product and the number of frames of imaging in the prior art are limited by the electronic optical imaging system itself.

Technical solutions

To achieve the above objective, the first aspect of the present invention provides an ultra-high-speed optical parametric amplification optical imaging system, including a light source system, a light splitting delay system, an optical parametric amplification system, and an image recording system;

The light source system includes an ultrashort pulse laser and a continuous or long pulse laser. The ultrashort pulse laser is used to output an ultrashort pulse laser and is incident on the optical parametric amplification system, and the continuous or long pulse laser is used to output Continuous or long pulse laser and incident to the split light delay system;

The light splitting delay system is used for splitting and delaying the incident continuous or long pulse laser to obtain multiple sub-beams carrying object information with a specific time delay, and the sub-beams are incident on the optical parameter Amplification system

The optical parametric amplification system is used for pumping the incident ultrashort pulse laser to perform non-collinear optical parametric amplification of the sub-beams to obtain an idle frequency optical array carrying object information with a specific time delay , The idle frequency light array is incident on the image recording system;

The image recording system is used for imaging the image of the object information with a specific time delay carried by the incident idle frequency light array.

Further, the ultra-short laser pulse is incident on a harmonic converter and partially converted into a high-order harmonic pulse, and the high-order harmonic pulse is used for the pump light of the subsequent optical parametric amplifier, and is passed through the harmonic converter. Another part of the unconverted ultra-short laser pulse is used to generate ultra-fast events. The output continuous or long-pulse laser irradiates the ultra-fast event placed on the object plane of the imaging system to carry the object information, and is incident on the split light delay system.

Further, the light splitting delay system includes: an imaging lens, a binary optical element beam splitter, a collimating lens, a beam delay array, and a shrinking cavity optical system;

The imaging lens is used to image the continuous or long pulse laser onto the surface of the secondary optical element beam splitter;

The secondary optical element beam splitter is used to split the imaged continuous or long-pulse laser into multiple sub-beams, and the multiple sub-beams are incident on the collimating lens;

The collimating lens is used to make the transmission directions of the plurality of sub-beams parallel to each other and enter the beam delay array;

The beam delay array is used to delay the incident multiple sub-beams to obtain multiple sub-beams carrying object information with a specific time delay, and the multiple sub-beams are incident on the shrinkage optical system;

The shrinkage cavity optical system is used to shrink a plurality of the sub-beams and enter the optical parametric amplification system.

Further, the beam delay array includes two stepped mirrors, and the two stepped mirrors are perpendicular to each other in the step direction.

Further, the parametric amplification system includes an optical retarder, a beam expander optical system, and an optical parametric amplification crystal;

The optical retarder is used to delay the incident multiple sub-beams and enter the beam expander optical system;

The beam expander optical system is used to expand the holes of the plurality of incident sub-beams and enter the optical parametric amplification crystal;

The optical parametric amplification crystal is used to use the ultrashort pulse laser as a pump to perform non-collinear optical parametric amplification of a plurality of incident sub-beams to obtain idle frequency light trains carrying object information with a specific time delay Array.

Further, the parametric amplification system further includes a mirror and a beam combiner located between the beam expander optical system and the optical parametric amplification crystal;

The reflecting mirror is used to reflect the plurality of sub-beams after the hole expansion of the beam expander optical system, and reflect them to the beam combiner;

The beam combiner is used to combine the incident multiple sub-beams and ultra-short pulse lasers, and enter the optical parametric amplification crystal.

Further, the image recording system includes a coupling optical system and a two-dimensional CCD array system;

The coupling optical system is used for imaging the image of the object information carried by the idle frequency optical array to the array recording surface of the two-dimensional CCD array system.

Beneficial effect

The beneficial effects of the present invention: by using a light splitting delay system to split and delay the incident continuous or long pulse laser, multiple sub-beams carrying object information with a specific time delay are obtained, and the optical parametric amplification system is further used for incident The ultrashort pulse laser is pumped to perform non-collinear optical parametric amplification of the multiple sub-beams to obtain idle frequency optical arrays carrying object information with a specific time delay. These idle frequency optical arrays are received by the image recording system. It can realize imaging of objects at different moments, and can also realize high spatial bandwidth product, high framing frequency and multiple imaging of more than ten frames, and realize ultra-high-speed optical imaging with picosecond or even femtosecond time resolution.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic structural diagram of an ultra-high-speed optical parametric magnification optical imaging system in an embodiment of the present invention;

2 is another structural schematic diagram of the ultra-high-speed optical parametric magnification optical imaging system in the embodiment of the present invention;

FIG. 3 is a schematic diagram of another structure of an ultra-high-speed optical parametric magnification optical imaging system in an embodiment of the present invention;

FIG. 4 is a schematic diagram of another structure of the ultra-high-speed optical parametric magnification optical imaging system in the embodiment of the present invention.

Embodiments of the present invention

In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the description The embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of the present invention.

Please refer to FIGS. 1 to 4, which are schematic structural diagrams of an ultra-high-speed optical parametric amplification optical imaging system in an embodiment of the present invention. The ultra-high-speed optical parametric amplification optical imaging system includes a light source system 101, a light splitting delay system 201, and an optical parametric amplification System 301 and image recording system 401.

Among them, the light source system 101 includes an ultrashort pulse laser 1011 and a continuous or long pulse laser 1012. The ultrashort pulse laser 1011 is used to output ultrashort pulse lasers, and the continuous or long pulse laser is used to output continuous or long pulse lasers, and ultrashort pulse lasers. As the pump light enters the optical parametric amplification system 301, the continuous or long pulse laser irradiates the ultrafast event placed on the object plane of the imaging system to carry the object information, and enters the split light delay system 201. The ultrashort pulse laser 1011 can It is a Ti: S regeneratively amplified femtosecond laser with an output of 1kHz, 35 fs, 3.5W, and 800nm. The continuous laser is a continuous laser with an output of 10 W, 1064nm, single longitudinal mode, single transverse mode, and linear polarization.

In the embodiment of the present invention, the ultra-short pulse laser 1011 is used as the pump light of the optical parametric amplification system 301 and the pump light that excites the ultra-fast time. The ultra-high-speed optical parametric amplification optical system further includes: high-order harmonic pulse 501 The sub-harmonic pulse 501 is used to partially convert the initial ultra-short pulse laser output by the ultra-short pulse laser into high-order harmonic pulse processing, and about 30% is converted into a 400nm beam, which is used for the pump of the subsequent optical parametric amplifier Puguang, the other part of the unconverted ultra-short laser pulse is used to generate ultra-fast events. At the same time, the output of continuous or long pulse laser irradiates the ultra-fast event placed on the object plane of the imaging system to carry the object information and enters the spectroscope时系统201。 Time system 201. Among them, the life of this ultrafast event is about picoseconds, so the 49-frame framing imaging requires that the exposure time of each frame is below 100 femtoseconds, and the recording interval is about 100 femtoseconds.

The light splitting delay system 201 is used to split and delay the incident continuous or long pulse laser to obtain multiple sub-beams carrying object information with a specific time delay. The sub-beams are incident on the optical parametric amplification system 301, where the splitting The time delay system 201 includes: an imaging lens 2011, a binary optical element beam splitter 2012, a collimator lens 2013, a beam delay array 2014 and a shrinkage optical system 2015, and a 4f confocal imaging system composed of the above, wherein the imaging lens 2011 is used to image the continuous or long pulse laser onto the surface of the secondary optical element beam splitter 2012, and the secondary optical element beam splitter 2012 is used to split the imaged continuous or long pulse laser into multiple sub-beams. The beam is incident on the collimating lens 2013. The collimating lens 2013 is used to make the transmission directions of the multiple sub-beams parallel to each other, and is incident to the beam retardation array 2014. The beam retardation array 2014 is used to delay the multiple incident sub-beams. The multiple sub-beams of the object information with a specific time delay are incident to the shrinkage cavity optical system 2015, and the shrinkage cavity optical system 2015 shrinks the multiple sub-beams and enters the optical parametric amplification system 301. Wherein, the beam delay array 2015 includes two stepped mirrors. The two stepped mirrors are perpendicular to each other in the step direction. The length of the optical delay time between each sub-beam is determined by changing the beam delay array material and adjusting the distance between the stepped mirrors. Among them, the continuous or long pulse laser incident to the light splitting delay system 201 carries the object information of the ultrafast event. The ultrafast event can be sampled by the binary optical element beam splitter 2012, and the beam is split into 7*7 beams of the same Sub-beams. These sub-beams pass through an optical delay array 2014 composed of 49 units, and enter the optical parametric amplification system 301 after shrinking holes. At the same time, each sub-beam arriving at the optical parametric amplification system carries object information at different moments. The framing time interval is determined by the optical retarder 3011 in the optical parametric amplification system 301.

In the embodiment of the present invention, the light beam is finally delayed through the functions of the internal components of the light splitting delay system 201, and multiple sub-beams are incident on the optical parametric amplification system 301.

The optical parametric amplification system 301 is used for pumping the incident ultrashort pulse laser to perform non-collinear optical parametric amplification of the sub-beams to obtain an idle frequency optical array carrying object information with a specific time delay, and the idle frequency optical array It is incident on the image recording system 401, and the image recording system 401 is used for imaging the image of the object information with a specific time delay carried by the incident idle frequency light array. Among them, the parametric amplification system includes an optical retarder 3011, a beam expander optical system 3012, a mirror 3013, a beam combiner 3014, and an optical parametric amplification crystal 3015. When an ultrashort pulse laser is incident on the parametric amplification system 301, it is an ultrashort pulse laser It is incident on the optical retarder 3011. The optical retarder 3011 delays the incident multiple sub-beams and enters the beam expander optical system. The beam expander optical system 3012 expands the holes of the incident multiple sub-beams and enters the mirror 3013. The mirror 3013 reflects the multiple sub-beams after the expansion of the beam expander optical system 3012 and reflects them to the beam combiner 3014. The beam combiner 3014 is used to combine the incident multiple sub-beams and ultra-short pulse lasers. , And incident on the optical parametric amplification crystal 3015, the optical parametric amplification crystal is used to use the ultrashort pulse laser as the pump light to perform non-collinear optical parametric amplification of the incident multiple sub-beams to obtain the object information with a specific time delay The idle frequency light array is incident to the beam expanding optical system 3012 and the multiple incident sub-beams are expanded, and finally incident to the image recording system. Correspondingly, each idle frequency light carries object information derived from each signal light.

In the embodiment of the present invention, by adjusting the mirror 3013 and the beam combiner 3014, the size of the non-collinear angle between the ultrashort pulse laser and the multiple sub-beams can be adjusted, which is used to realize the light with the best bandwidth and gain. With parametric amplification, adjusting the optical retarder 3011 can control the time delay between the pump light and the sub-beam.

In the embodiment of the present invention, the image recording system 401 includes a coupling optical system 4011 and a two-dimensional CCD array system 4012, and the coupling optical system 4011 is used to image the image of the object information carried by the incident idle frequency light array to the two-dimensional CCD The array recording surface of the array system 4012 can realize that these light beams are received by the CCD camera combination array after passing through the optical imaging coupling system 4011 to obtain multiple sequential images with specific delays, for example, 49 sub-frame sequential images are obtained.

The light passing through the light source system is incident on the splitting delay system and the optical parametric amplification system respectively, and finally by using the beam delay array to make these sub-beams carry the object information with a certain time delay and arrive at the same place at the same time, and then use the ultra-short pulse laser to perform Pump sampling can realize the imaging of the object at different moments. It can achieve high spatial bandwidth product, high framing frequency and multi-frame imaging with more than ten frames, and realize ultra-high-speed optical imaging with picosecond or even femtosecond time resolution. , While greatly improving the efficiency of imaging.

The above are only the embodiments of the present invention and do not limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the description and drawings of the present invention, or directly or indirectly applied to other related technical fields, The same reasoning is included in the scope of patent protection of the present invention.

Claims (7)

An ultra-high-speed optical parametric amplification optical imaging system, which is characterized in that it includes a light source system, a light splitting delay system, an optical parametric amplification system and an image recording system; The light source system includes an ultrashort pulse laser and a continuous or long pulse laser. The ultrashort pulse laser is used to output ultrashort pulse laser and is incident on the optical parametric amplification system. The continuous or long pulse laser is used to output continuous Or a long pulse laser and incident on the light splitting delay system; The light splitting delay system is used for splitting and delaying the incident continuous or long pulse laser to obtain multiple sub-beams carrying object information with a specific time delay, and the sub-beams are incident on the optical parameter Amplification system The optical parametric amplification system is used for pumping the incident ultrashort pulse laser to perform non-collinear optical parametric amplification of the sub-beams to obtain an idle frequency optical array carrying object information with a specific time delay , The idle frequency light array is incident on the image recording system; The image recording system is used for imaging the image of the object information with a specific time delay carried by the incident idle frequency light array. The ultra-high-speed optical parametric amplification optical imaging system of claim 1, wherein the ultra-short laser pulse is incident on a harmonic converter and converted into a high-order harmonic pulse, and the high-order harmonic pulse is used for In the subsequent pump light of the optical parametric amplifier, another part of the ultrashort laser pulse that is not converted by the harmonic converter is used to generate an ultrafast event, and the output continuous or long pulse laser is irradiated on the object plane of the imaging system The ultrafast event carries the object information and is incident on the light splitting delay system. The ultra-high-speed optical parametric magnification optical imaging system of claim 1, wherein the light splitting delay system comprises: an imaging lens, a binary optical element beam splitter, a collimating lens, a beam delay array, and shrinkage optics system; The imaging lens is used to image the continuous or long pulse laser onto the surface of the secondary optical element beam splitter; The secondary optical element beam splitter is used to split the imaged continuous or long-pulse laser into multiple sub-beams, and the multiple sub-beams are incident on the collimating lens; The collimating lens is used to make the transmission directions of the plurality of sub-beams parallel to each other and enter the beam delay array; The beam delay array is used to delay the incident multiple sub-beams to obtain multiple sub-beams carrying object information with a specific time delay, and the multiple sub-beams are incident on the shrinkage optical system; The shrinkage cavity optical system is used to shrink a plurality of the sub-beams and enter the optical parametric amplification system. The ultra-high-speed optical parametric magnification optical imaging system of claim 3, wherein the beam delay array includes two stepped mirrors, and the step directions of the two stepped mirrors are perpendicular to each other. The ultra-high-speed optical parametric amplification optical imaging system of claim 1, wherein the parametric amplification system comprises an optical retarder, a beam expander optical system, and an optical parametric amplification crystal; The optical retarder is used to delay the incident high-order harmonic pulse and enter the beam expander optical system; The beam expander optical system is used to expand the hole of the incident high-order harmonic pulse and enter the optical parametric amplification crystal; The optical parametric amplification crystal is used to use the ultrashort pulse laser as a pump to perform non-collinear optical parametric amplification of a plurality of incident sub-beams to obtain idle frequency light trains carrying object information with a specific time delay Array. The ultra-high-speed optical parametric amplification optical imaging system of claim 5, wherein the parametric amplification system further comprises a mirror and a beam combiner located between the beam expander optical system and the optical parametric amplification crystal ； The reflecting mirror is used to reflect the plurality of sub-beams after the hole expansion of the beam expander optical system, and reflect them to the beam combiner; The beam combiner is used for combining the incident multiple sub-beams and the high-order harmonic pulses, and incident them to the optical parametric amplification crystal. The ultra-high-speed optical parametric amplification optical imaging system of claim 1, wherein the image recording system comprises a coupling optical system and a two-dimensional CCD array system; The coupling optical system is used for imaging the image of the object information carried by the idle frequency optical array to the array recording surface of the two-dimensional CCD array system.