阅读说明：本技术 一种基于热电制冷的温度调谐型Fe:ZnSe激光器 (Thermoelectric refrigeration-based temperature tuning type Fe-ZnSe laser ) 是由 马杰 沈吉 杨帆 高泰鹏 唐定远 沈德元 于 2021-08-23 设计创作，主要内容包括：本发明公开了激光器领域的一种基于热电制冷的温度调谐型Fe:ZnSe激光器,包括Fe:ZnSe晶体、泵浦激光源、半导体热电制冷装置、激光谐振腔；所述泵浦激光源发射出泵浦光,并经过泵浦光整形耦合元件后入射至Fe:ZnSe晶体；所述Fe:ZnSe晶体设置于激光谐振腔内；所述Fe:ZnSe晶体固定在热沉上,热沉与半导体热电制冷装置连接；所述Fe:ZnSe晶体、热沉设置于真空腔内；通过半导体热电制冷器件大范围调控激光器中Fe:ZnSe晶体运转温度,从而实现对其不同光谱荧光寿命的有效调控,进而获得不同波长的可调谐中红外激光输出；半导体热电制冷器件温度响应时间快、结构简单紧凑、成本低,十分有利于发展不同应用需求的高性能可调谐中红外光源。(The invention discloses a thermoelectric refrigeration-based temperature tuning type Fe: ZnSe laser in the field of lasers, which comprises a Fe: ZnSe crystal, a pump laser source, a semiconductor thermoelectric refrigeration device and a laser resonant cavity; the pump laser source emits pump light, and the pump light is incident to the Fe: ZnSe crystal after passing through the pump light shaping coupling element; the Fe: ZnSe crystal is arranged in the laser resonant cavity; the Fe: ZnSe crystal is fixed on a heat sink, and the heat sink is connected with the semiconductor thermoelectric refrigerating device; the Fe, ZnSe crystal and the heat sink are arranged in the vacuum cavity; the operating temperature of the Fe: ZnSe crystal in the laser is regulated and controlled in a large range by the semiconductor thermoelectric refrigerating device, so that the effective regulation and control of the fluorescence life of different spectra of the laser are realized, and further, the tunable mid-infrared laser output with different wavelengths is obtained; the semiconductor thermoelectric refrigerating device has the advantages of quick temperature response time, simple and compact structure and low cost, and is very favorable for developing high-performance tunable mid-infrared light sources with different application requirements.)

1. A temperature tuning type Fe: ZnSe laser based on thermoelectric refrigeration is characterized by comprising a Fe: ZnSe crystal (7), a pump laser source (1), a semiconductor thermoelectric refrigeration device and a laser resonant cavity; the pump laser source (1) emits pump light, and the pump light enters the Fe: ZnSe crystal (7) after passing through the pump light shaping coupling element; the Fe: ZnSe crystal (7) is arranged in the laser resonant cavity; the Fe: ZnSe crystal (7) is fixed on a heat sink (8), and the heat sink (8) is connected with the semiconductor thermoelectric refrigerating device; the Fe: ZnSe crystal (7) and the heat sink (8) are arranged in the vacuum cavity.

2. The thermo-electric refrigeration based temperature tuning type Fe: ZnSe laser according to claim 1, wherein a concave input mirror (4) is arranged in the direction of incidence of the pump light of the Fe: ZnSe crystal (7); an output coupling mirror (10) is arranged in the pump light emitting direction of the Fe: ZnSe crystal (7); the laser resonant cavity is formed between the concave surface input mirror (4) and the output coupling mirror (10).

3. The thermo-electric refrigeration based temperature tuned Fe: ZnSe laser according to claim 2, wherein said concave input mirror (4) is coated with a high transmission film for pump light band with a high transmission rate > 95%, and a broadband high reflection film for laser band with a reflection film reflectivity > 99.8%, and said planar output coupling mirror (10) is coated with a broadband partial reflection film for laser band with a reflection film reflectivity of 90% and a transmission film transmissivity of 10%.

4. The thermo-electric refrigeration based temperature tuning type Fe: ZnSe laser according to claim 1, further comprising a plurality of cavity mirrors; and pump light among the cavity mirrors oscillates to form a laser resonant cavity.

5. ZnSe laser of a temperature tunable type based on thermoelectric cooling as claimed in claim 1, characterized in that the vacuum chamber is arranged in a vacuum vessel (9); two sealing window sheets for laser to penetrate are arranged on the vacuum container (9), and the window sheets are fluoride crystals or sesquioxide ceramics; and the inner side and the outer side of the window sheet are plated with anti-reflection films of laser wave bands.

6. The thermo-electric refrigeration based temperature tuning type Fe: ZnSe laser according to claim 1 or 5, wherein a vacuum degree in the vacuum chamber is 0.1 to 100 Pa.

7. The ZnSe laser of claim 1, wherein the pump light shaping coupling element comprises two convex lenses; the two convex lenses are arranged between the Fe: ZnSe crystal (7) and the pump laser source (1).

8. The thermo-electric refrigeration based temperature-tuned Fe: ZnSe laser according to claim 1, wherein Fe in said Fe: ZnSe crystal (7)²⁺The doping concentration of (A) is 1 to 50 x 10¹⁸cm^-3。

9. ZnSe laser based on thermoelectric cooling as claimed in claim 1, wherein the semiconductor thermoelectric cooling device adjusts the temperature by controlling the current and voltage.

10. The thermo-electric refrigeration based temperature tuned Fe: ZnSe laser according to claim 1, wherein said pump laser source (1) is Er: ZBLAN fiber laser or Er: Y₂O₃A laser or Er, a YAG laser or a DF/HF chemical laser.

Technical Field

The invention belongs to the technical field of lasers, and particularly relates to a Fe-ZnSe crystal laser.

Background

The mid-infrared radiation in the wave band of 3-5 microns is positioned in a transmission window with high atmospheric transmittance, and the ideal atmospheric transmission characteristic enables the laser in the wave band to have important application value in the fields of atmospheric environment monitoring, medical treatment (such as biological tissue ablation), laser radar, space optical communication and the like. In addition, in practical application, the laser system with fixed wavelength often can not well meet the practical application requirements of people, such as laser radar and high-precision spectral analysis, and the like, when the light source stability is required to be good and the damage resistance is strong, people also require the wavelength adjustability of the light source to be realized, so that the measurement and application range is wider, and the use is more flexible. Therefore, it is an object of research and effort to obtain stable and high quality tunable mid-infrared laser.

Currently, there are three main methods for obtaining tunable mid-infrared laser: a System using a laser resonator internal Mechanical movable part such as a diffraction grating, a prism, an etalon, or a Micro Electro Mechanical System (MEMS) as a wavelength tuning unit; the system for adjusting by using the optical device which is not movable in the cavity comprises a magneto-optical device, an acousto-optical device and an electro-optical device for wavelength tuning; for a semiconductor laser in a middle infrared band, the wavelength is often selected by changing the injection current, so as to realize the output of middle infrared laser with different wavelengths. Among the three main wavelength tuning methods, the technology of adjusting the wavelength by mechanically adjusting the grating, the prism and the like has very poor interference resistance to mechanical shock and vibration, and can cause short-term and even long-term performance instability, thereby influencing the output power of the laser and bringing about energy loss; the method of using magneto-optical device, acousto-optic device, electro-optic device and other devices to tune wavelength inevitably brings certain intra-cavity loss, and further influences the output efficiency and power of the laser. In addition, although the common intermediate infrared semiconductor laser can realize a wide tunable range through an electric control mode, the output power of the common intermediate infrared semiconductor laser is low, and the application field of the common intermediate infrared semiconductor laser is limited.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the thermoelectric refrigeration-based temperature tuning type Fe: ZnSe laser, which realizes tunable wavelength output by adjusting the operating temperature of the Fe: ZnSe crystal without introducing an additional wavelength tuning device, has the characteristics of simple and compact system structure, high reliability, low cost and the like, and can realize wide-range mid-infrared laser output.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a temperature tuning type Fe: ZnSe laser based on thermoelectric refrigeration comprises a Fe: ZnSe crystal, a pump laser source, a semiconductor thermoelectric refrigeration device and a laser resonant cavity; the pump laser source emits pump light, and the pump light is incident to the Fe: ZnSe crystal after passing through the pump light shaping coupling element; the Fe: ZnSe crystal is arranged in the laser resonant cavity; the Fe: ZnSe crystal is fixed on a heat sink, and the heat sink is connected with the semiconductor thermoelectric refrigerating device; the Fe: ZnSe crystal and the heat sink are arranged in the vacuum cavity.

Preferably, a concave input mirror is arranged in the pumping light incidence direction of the Fe: ZnSe crystal; an output coupling mirror is arranged in the pump light emitting direction of the Fe: ZnSe crystal; the laser resonant cavity is formed between the concave input mirror and the output coupling mirror.

Preferably, the concave input mirror is plated with a high-transmission film for a pump light wave band, the transmission rate of the high-transmission film is greater than 95%, and a broadband high-reflection film for a laser wave band, the reflection rate of the reflection film is greater than 99.8%, the plane output coupling mirror is plated with a broadband partial-reflection film for the laser wave band, the reflection rate of the broadband partial-reflection film is 90%, and the transmission rate of the broadband partial-reflection film is 10%.

Preferably, the device further comprises a plurality of cavity mirrors; and pump light among the cavity mirrors oscillates to form a laser resonant cavity.

Preferably, the vacuum chamber is arranged in a vacuum container; two sealed window sheets for laser to penetrate are arranged on the vacuum container, and the window sheets are fluoride crystals or sesquioxide ceramics; and the inner side and the outer side of the window sheet are plated with anti-reflection films of laser wave bands.

Preferably, the vacuum degree in the vacuum cavity is 0.1-100 Pa.

Preferably, the pump light shaping coupling element comprises two convex lenses; one surface of the convex lens is set as a plane; the other surface of the convex lens is a convex surface; the convex surfaces of the two convex lenses are oppositely arranged; the two convex lenses are arranged between the Fe: ZnSe crystal and the pump laser source.

Preferably, Fe in the Fe: ZnSe crystal²⁺The doping concentration of (A) is 1 to 50 x 10¹⁸cm^-3。

Preferably, the semiconductor thermoelectric refrigerating device adjusts the temperature by controlling current and voltage.

Preferably, the pump laser source is an Er: ZBLAN fiber laser or Er: Y₂O₃A laser or Er, a YAG laser or a DF/HF chemical laser.

Compared with the prior art, the invention has the following beneficial effects:

according to the strong dependence of the fluorescence lifetime of the Fe: ZnSe crystal on the temperature, the operating temperature of the Fe: ZnSe crystal in the laser is regulated and controlled in a large range by the semiconductor thermoelectric refrigerating device, so that the effective regulation and control of the fluorescence lifetime of different spectrums of the Fe: ZnSe crystal are realized, and further, the tunable mid-infrared laser output with different wavelengths is obtained; the semiconductor thermoelectric refrigerating device has the advantages of quick temperature response time, simple and compact structure and low cost, and is very favorable for developing high-performance tunable mid-infrared light sources with different application requirements.

Drawings

FIG. 1 is a structural diagram of a temperature-tuned Fe: ZnSe laser based on thermoelectric refrigeration according to an embodiment of the present invention;

in the figure: 1 is a pump laser source; 2 is a first convex lens; 3 is a second convex lens; 4 is a concave input mirror; 5 is a first window sheet; 6 is a second window sheet; 7 is Fe: ZnSe crystal; 8 is a heat sink; 9 is a vacuum container; and 10 is an output coupling mirror.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

It should be noted that in the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the present invention but do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. As used in the description of the present invention, the terms "front," "back," "left," "right," "up," "down" and "in" refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

As shown in figure 1, a temperature tuning type Fe: ZnSe laser based on thermoelectric refrigeration is sequentially provided with a pump laser source 1, a pump light shaping coupling element, a concave input mirror 4, a Fe: ZnSe crystal 7 and an output coupling mirror 10; the pump laser source 1 can be Er: ZBLAN fiber laser or Er: Y₂O₃The laser can also be Er, YAG laser or DF/HF chemical laser; the pump laser source 1 emits pump light, and the pump light is incident to the Fe: ZnSe crystal 7 after passing through the pump light shaping coupling element; the Fe: ZnSe crystal 7 is a transition metal doped II-VI group sulfide crystal; fe in the Fe: ZnSe crystal 7²⁺The doping concentration of (A) is 1 to 50 x 10¹⁸cm^-3(ii) a In order to reduce loss and increase the absorption of the crystal to pump light, two light-passing surfaces of the Fe: ZnSe crystal 7 are coated with antireflection films.

The pump light shaping coupling element comprises a first convex lens 2 and a second convex lens 3, and is mainly used for collimating and focusing pump light to change the size of a pump light spot mode at a crystal, so that better mode matching is realized, a laser system can efficiently operate in a fundamental mode, and a light beam meeting laser oscillation is obtained.

The laser resonant cavity is formed between the concave input mirror 4 and the output coupling mirror 10; the concave input mirror 4 is plated with a high-transmission film for a pump light wave band, the transmittance of the high-transmission film is more than 95%, and a broadband high-reflection film for a laser wave band, the reflectance of the reflection film is more than 99.8%, the plane output coupling mirror 10 is plated with a broadband partial reflection film for the laser wave band, the reflectance of the broadband partial reflection film is 90%, and the transmittance of the broadband partial reflection film is 10%; the Fe: ZnSe crystal 7 is arranged in the laser resonant cavity; the Fe: ZnSe crystal 7 is fixed on a heat sink 8, and the heat sink 8 is connected with a semiconductor thermoelectric refrigerating device; the semiconductor thermoelectric refrigerating device adjusts the temperature by controlling the current and the voltage, and the semiconductor thermoelectric refrigerating device is adopted to change the running temperature of the Fe: ZnSe crystal 7 in a large range, so that the effective regulation and control of the fluorescence life of different spectrums of the semiconductor thermoelectric refrigerating device are realized, and the tunable mid-infrared laser output with different wavelengths is obtained.

The Fe: ZnSe crystal 7 and the heat sink 8 are arranged in a vacuum cavity of the vacuum container 9; the vacuum container 9 is provided with a first window sheet 5 and a second window sheet 6 which are sealed and are used for laser to penetrate through, and the first window sheet 5 and the second window sheet 6 are made of fluoride crystals or sesquioxide ceramics; the inner side and the outer side of the first window sheet 5 and the second window sheet 6 are plated with anti-reflection films of a middle infrared laser band of 3-5 microns; the vacuum degree in the vacuum cavity is 0.1-100 Pa.

The working principle is as follows: the invention utilizes the strong dependence relationship between the fluorescence lifetime of the Fe: ZnSe crystal 7 and the temperature, and adopts the semiconductor thermoelectric refrigerating device to change the operating temperature of the Fe: ZnSe crystal in a large range, thereby realizing the effective regulation and control of the fluorescence lifetime of different spectra, and further obtaining the tunable mid-infrared laser output with different wavelengths; compared with the traditional wavelength tuning method using devices such as gratings, prisms and the like, the invention can realize the continuously tunable intermediate infrared laser output with wide range and high reliability, and has simple structure and low cost.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.