CN210723684U

CN210723684U - Hundred picoseconds laser without pulse trailing

Info

Publication number: CN210723684U
Application number: CN201922173765.6U
Authority: CN
Inventors: 白振旭; 陈彬; 齐瑶瑶; 丁洁; 王雨雷; 吕志伟
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2020-06-09
Anticipated expiration: 2029-12-06

Abstract

The utility model discloses a hundred picoseconds laser instrument of no pulse trailing, hundred picoseconds laser instrument includes: the pump source outputs linear polarization pump pulse laser with the duration of nanosecond, and the pump pulse laser enters the SBS pulse compressor through the first optical isolator; the pump light generates backward stimulated Brillouin scattering in the SBS pulse compressor, and the pulse time is compressed to picosecond level; and the compressed pulse laser enters the pulse tailing suppressor after passing through the second optical isolator, and optical breakdown occurs in the pulse tailing suppressor when the pulse energy reaches the pulse peak. The utility model overcomes traditional high-energy SBS pulse compression system output pulse has the problem of serious tailing, obtains to have more narrowly than the pulse width of the direct output of traditional SBS pulse compression, more smooth pulse waveform.

Description

Hundred picoseconds laser without pulse trailing

Technical Field

The utility model relates to a laser instrument field especially relates to a hundred picosecond laser instruments of no pulse trailing.

Background

Stimulated Brillouin Scattering (SBS) is well known for its excellent properties in phase conjugation, pulse compression, temporal and spatial shaping of beams, slow light and beam synthesis etc., and has the characteristics of simple structure, self-pumping and amplification etc. SBS pulse compression is a brillouin amplification process and the conversion efficiency of a pump beam into a Stokes (Stokes) beam is high while the pulse duration is significantly reduced. By this technique a linearly polarized incident beam is injected into the SBS pulse compressor and focused into the SBS unit, producing a backscattered Stokes beam at the focal point. According to the brillouin amplification principle, a backscattered Stokes beam depletes a pump beam at normal incidence (propagating back to the Stokes light) during interaction, in which the rising edge of the Stokes pulse sweeps over and depletes the remainder of the pump pulse (the pulse trailing edge), converting the incoming pump pulse into a time-compressed Stokes pulse. Various SBS pulse compressors are designed according to different pumping conditions and output parameters, such as a waveguide structure, a single-cell pulse compressor, a dual-cell pulse compressor, a compact single-cell scheme, an expandable dual-cell scheme and the like.

Furthermore, by combining the Master Oscillator Power Amplifier (MOPA) with the SBS pulse compressor, the SBS unit also provides distortion compensation as a stimulated brillouin scattering phase conjugate mirror (SBS-PCM) to obtain high beam quality amplified and time compressed output. With increasing peak power, SBS pulse compression can achieve higher nonlinear frequency conversion efficiency. The combination of SBS pulse compression and other non-linear frequency conversion techniques helps to extend the wavelength coverage of mature pump sources with high peak power, suitable for sub-nanosecond pulse applications, including: medical treatment, communication, laser radar, laser shock peening, space debris detection, inertial constraint fusion and the like.

Although the conventional SBS pulse compressor can achieve high-efficiency pulse compression, the waveform of the output pulse is often accompanied by a certain tail (tail modulation) due to factors such as insufficient absorption of the Stokes light beam on the pump light energy as the incident energy increases. Although the rising edge of the compressed pulse can reach picosecond magnitude, the tail of the pulse is difficult to further compress the whole duration (full width at half maximum) of the pulse due to the trailing of the tail, and the peak power of the laser pulse is reduced, so that the application of the SBS pulse compression laser in various fields is limited. Therefore, the pulse-width-controllable large-energy SBS pulse compression hundred picosecond laser without pulse tailing is realized by introducing the pulse tailing inhibiting device, and the pulse-width-controllable large-energy SBS pulse compression hundred picosecond laser has important practical value and significance.

SUMMERY OF THE UTILITY MODEL

The utility model provides a hundred picosecond laser instrument of no pulse tailing, at first produce the pulse through SBS pulse compressor promptly and rise the pulse laser output of following hundred picoseconds at the picosecond magnitude, then utilize a pulse tailing to restrain the hundred picosecond laser of medium pond after with SBS pulse compressor compression and go the tailing, make the wave form more sharp-pointed, pulse duration shorter and controllable at the picosecond magnitude, see following description for details:

a hundred picosecond laser without pulse tail, the hundred picosecond laser comprising:

the pump source outputs linear polarization pump pulse laser with the duration of nanosecond, and the pump pulse laser enters the SBS pulse compressor through the first optical isolator;

the pump light generates backward stimulated Brillouin scattering in the SBS pulse compressor, and the pulse time is compressed to picosecond level;

and the compressed pulse laser enters the pulse tailing suppressor after passing through the second optical isolator, and optical breakdown occurs in the pulse tailing suppressor when the pulse energy reaches the pulse peak.

Wherein the SBS pulse compressor comprises: a polarizing plate or a polarization beam splitter prism, a quarter-wave plate or a Faraday rotator, a convex lens and a liquid Brillouin medium pool.

In another embodiment, the SBS pulse compressor includes: the device comprises a polaroid or a polarization beam splitter prism, a quarter-wave plate or a Faraday rotator, a convex lens, an SBS liquid Brillouin generation pool and an SBS liquid Brillouin amplification pool.

In another embodiment, the SBS pulse compressor includes: a polarizing plate or a polarization beam splitter prism, a quarter-wave plate or a Faraday rotator, a liquid Brillouin medium pool and a concave reflector.

Further, the pulse tail suppressor includes: a polaroid or a polarization beam splitter prism and a pulse tailing suppression medium pool.

In another embodiment, the pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism, a pulse tailing suppression medium pool and a convex lens.

In another embodiment, the pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism, a pulse tailing inhibiting medium pool and a dichroic mirror.

In another embodiment, the pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism, a pulse tailing suppression medium pool, a convex lens and a dichroic mirror.

The utility model provides a technical scheme's beneficial effect is:

1. according to the device, by selecting a pulse tailing suppressor filled with a liquid or gas medium, when the rising edge energy of input SBS pulse compression laser reaches a medium optical breakdown threshold (the liquid or gas medium cannot be damaged even if optical breakdown occurs), the falling edge tailing of the pulse is suppressed, so that the pulse waveform is sharper and the pulse duration is shorter;

2. the device can obviously inhibit the amplification of the tail of the pulse, overcomes the problem that the pulse output by the traditional large-energy SBS pulse compression system has serious tailing, and obtains a pulse waveform which is narrower and smoother than the pulse width directly output by the traditional SBS pulse compression.

Drawings

FIG. 1 is a schematic diagram of a hundred picosecond laser without pulse tail;

FIG. 2 is a schematic diagram of a compressor configuration for a single-cell configuration;

FIG. 3 is a schematic diagram of a compressor configuration for a dual tank configuration;

FIG. 4 is a schematic view of a compressor with a concave reflector;

FIG. 5 is a schematic diagram of a pulse tail suppressor structure;

FIG. 6 is a schematic diagram of a pulse tail suppressor with focusing function;

FIG. 7 is a schematic diagram of a pulse tail suppressor with spectroscopic effect;

fig. 8 is a schematic diagram of a pulse tail suppressor with focusing and beam splitting functions.

In the drawings, the components represented by the respective reference numerals are listed below:

1. a pulsed laser pump source; 2. 4, optical isolators (a first optical isolator and a second optical isolator);

3. an SBS pulse compressor; 5. A pulse tail suppressor;

3-1, 5-1, a polarizing plate or a polarizing beam splitter prism; 3-2, a quarter wave plate or a faraday rotator;

3-3, 5-3, convex lens; 3-4, an SBS liquid Brillouin medium pool;

3-5, an SBS liquid Brillouin generation pool; 3-6, an SBS liquid Brillouin amplification pool;

3-7, a concave reflector; 5-2, pulse tailing inhibition medium pool.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention are described in further detail below.

The overall working principle of the hundred picosecond laser is as follows: the pumping source 1 outputs linear polarization pumping pulse laser with nanosecond duration, the pumping pulse laser enters the SBS pulse compressor 3 through the first optical isolator 2, the pumping light generates backward stimulated Brillouin scattering in the SBS pulse compressor 3, and pulse time is compressed to picosecond level; the pulse laser after the compression firstly passes through the second optical isolator 4 and then enters the pulse trailing suppressor 5, when the pulse energy reaches the pulse peak, the optical breakdown occurs in the pulse trailing suppressor 5, the purpose of suppressing the pulse trailing is achieved, and the pulse waveform is more sharp and the pulse duration is shorter.

To SBS pulse compressor 3, the utility model discloses a innovation point lies in the phonon life-span, brillouin gain, brillouin linewidth isoparametric through liquid or gaseous medium, compresses the whole duration of pulse width to hundred picoseconds, and the pulse width that rises this moment along is the picosecond magnitude. And the time of the pulse entering the pulse tail suppressor 5 is controlled by matching with the pulse tail suppressor 5, so that the optical breakdown is ensured to occur at the pulse peak, the pulse tail is suppressed as much as possible, and the loss of the pulse tail suppression to the peak power is reduced.

The utility model discloses a can use common medium pond structure to realize the SBS pulse compressor 3 of the utility model discloses a referring to fig. 2, fig. 3 and fig. 4, common SBS pulse compressor 3's structure includes: a polarizing film or a polarization beam splitter prism 3-1, a quarter wave plate or a Faraday optical rotator 3-2, a convex lens 3-3, a liquid Brillouin medium pool 3-4, an SBS liquid Brillouin generation pool 3-5, an SBS liquid Brillouin amplification pool 3-6, a concave reflector 3-7 and other components.

The pump light undergoes backward stimulated brillouin scattering in the SBS pulse compressor 3 and the pulse time is compressed to the picosecond order.

The pulse laser after pulse time compression sequentially passes through a quarter-wave plate or a Faraday optical rotator 3-2 and a polarizing plate or a polarization beam splitter prism 3-1 and then enters a pulse tailing suppressor 5 through a second optical isolator 4.

Another innovative point of the present invention is the design of the pulse tail suppressor 5, see fig. 5, 6, 7, 8, the pulse tail suppressor 5 includes: 5-1 parts of a polarizing film or a polarization beam splitter prism, 5-2 parts of a pulse tailing inhibition medium pool, 5-3 parts of a convex lens, 5-4 parts of a dichroic mirror and the like.

According to the laser pulse energy intensity and the nonlinear effect of the pulse passing through the pulse tail suppressor, the pulse tail suppressor 5 has four specific embodiments: when no Stimulated Raman Scattering (SRS) is generated in the pulse-tail suppression dielectric pool 5-2 and the pulse laser energy density is enough to cause optical breakdown at the pulse peak, the structure is shown in fig. 5; when no SRS is generated in the pulse tailing suppression medium pool 5-2, but the energy density of the pulse laser is not enough to generate optical breakdown at the pulse peak, the structure is shown in FIG. 6; when SRS is generated in the pulse tailing suppression medium pool 5-2, but the energy density of the pulse laser is not enough to generate optical breakdown at the pulse peak, the structure is shown in FIG. 7; when SRS is generated in the pulse tail suppression medium pool 5-2 but the energy density of the pulse laser is not enough to cause optical breakdown at the pulse peak, the structure is shown in fig. 8.

The pulse laser after SBS compression is achieved through laser-induced breakdown, when the pulse laser is transmitted through the pulse tailing suppressor 5, breakdown is achieved through the Stokes light beam leading edge and the medium action of the pulse tailing suppressor, and the trailing edge of the pulse with the tailing cannot be normally output.

In summary, the pulse tail is suppressed when the pulse energy reaches the optical breakdown threshold, so as to reduce the low-intensity tail of the laser pulse. The utility model discloses a hundred picoseconds laser instrument of no tailing produces hundred picoseconds pulse output through SBS pulse compressor, gets rid of the pulse tailing behind the SBS compression through the pulse tailing inhibitor based on optics breakdown on this basis, makes the wave form more sharp-pointed, pulse duration shorter.

The embodiment of the utility model provides a except that doing special explanation to the model of each device, the restriction is not done to the model of other devices, as long as can accomplish the device of above-mentioned function all can.

Those skilled in the art will appreciate that the drawings are only schematic illustrations of preferred embodiments, and the embodiments of the present invention are given the same reference numerals and are not intended to represent the merits of the embodiments.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A hundred picosecond laser without pulse tail, said hundred picosecond laser comprising:

2. The hundred picosecond laser without pulse tail of claim 1, wherein said SBS pulse compressor comprises:

a polarizing plate or a polarization beam splitter prism, a quarter-wave plate or a Faraday rotator, a convex lens and a liquid Brillouin medium pool.

3. The hundred picosecond laser without pulse tail of claim 1, wherein said SBS pulse compressor comprises:

the device comprises a polaroid or a polarization beam splitter prism, a quarter-wave plate or a Faraday rotator, a convex lens, an SBS liquid Brillouin generation pool and an SBS liquid Brillouin amplification pool.

4. The hundred picosecond laser without pulse tail of claim 1, wherein said SBS pulse compressor comprises:

a polarizing plate or a polarization beam splitter prism, a quarter-wave plate or a Faraday rotator, a liquid Brillouin medium pool and a concave reflector.

5. The hundred picosecond laser without pulse tail of claim 1, wherein said pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism and a pulse tailing suppression medium pool.

6. The hundred picosecond laser without pulse tail of claim 1, wherein said pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism, a pulse tailing suppression medium pool and a convex lens.

7. The hundred picosecond laser without pulse tail of claim 1, wherein said pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism, a pulse tailing inhibiting medium pool and a dichroic mirror.

8. The hundred picosecond laser without pulse tail of claim 1, wherein said pulse tail suppressor comprises: a polaroid or a polarization beam splitter prism, a pulse tailing suppression medium pool, a convex lens and a dichroic mirror.