CN218334710U

CN218334710U - Spatial incoherent double-path beam combining system of intermediate infrared quantum cascade laser

Info

Publication number: CN218334710U
Application number: CN202223098794.9U
Authority: CN
Inventors: 王雨雷; 李志宽; 李森森; 李凯; 岳剑峰; 孟子博; 吕志伟
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2022-11-22
Filing date: 2022-11-22
Publication date: 2023-01-17
Anticipated expiration: 2032-11-22

Abstract

The utility model provides a beam system is closed to incoherent double-circuit in well infrared quantum cascade laser instrument space, including quantum level laser meter, heat abstractor and laser instrument casing, quantum level laser meter and heat abstractor all set up inside the laser instrument casing, and quantum level laser meter sets up at the heat abstractor upside, and heat abstractor's thermistor sets up on quantum laser meter. The utility model discloses closed the light path of restrainting to space incoherent double-circuit and simplified, the lens installation is comparatively convenient, only needs infrared reflector in two aspheric surface collimating lens and two just can reach the purpose of restrainting in the far field, simple structure, and the stack of fine realization double-circuit laser power under the condition of not considering lens and light beam transmission loss, when obtaining higher power output, does not change the light beam quality. And simultaneously, the utility model discloses a heat abstractor has set up semiconductor cooler and circulating water cooling plant, guarantees the normal work of infrared quantum cascade laser in the double-circuit.

Description

Spatial incoherent double-path beam combining system of intermediate infrared quantum cascade laser

Technical Field

The utility model relates to a mid-infrared quantum cascade laser closes the technical field who restraints the system, especially relates to a mid-infrared quantum cascade laser space incoherent double-circuit closes and restraints system.

Background

The quantum cascade laser is a new type semiconductor laser, and can implement maser radiation of middle and far infrared wave band by means of its unique transition mode, so that it is mainly used in the fields of distance detection, atmospheric pollution monitoring, medical microimaging and infrared countermeasure. Nowadays, much research is carried out on the internal structure of the mid-infrared quantum cascade laser, and less research is carried out on the external integral beam combining system, so that how to develop a beam combining system with higher reliability is a difficulty nowadays.

The method comprises the following steps of firstly, solving the beam combination design problem of a multi-path quantum cascade laser, wherein the beam combination design problem comprises a method, an optical path, a lens and the like. The beam combination is a key technology for realizing high-power and high-brightness laser output of a quantum cascade laser, and the laser beam combination technology can be divided into two methods of coherent beam combination and incoherent beam combination according to coherence requirements and a beam combination mechanism of laser units participating in beam combination. The coherent combination beam has strict requirements on characteristics such as spectrum and polarization of the combination laser unit and has a complex structure, and the incoherent combination beam has a simple structure but the obtained light beam has a large size and poor quality. Therefore, how to obtain a more reliable beam combining system needs to consider the characteristics of the device to select a proper beam combining design.

Secondly, the heat dissipation and temperature control of the whole system are solved. The quantum cascade laser generates a great deal of heat in the working process, so that the device needs to be ensured to have good heat dissipation conditions and a temperature control system in the working process. The common heat dissipation method is

Air cooling, water cooling, semiconductor refrigeration and the like, but different methods have various advantages and disadvantages, such as too large air cooling interference, too low water cooling precision and too complex semiconductor refrigeration structure. Therefore, both heat dissipation and temperature control of the device require reliable design to achieve proper operation of the whole system.

The invention patent with publication number CN105071196B provides a narrow-linewidth beam combining module and a multi-wavelength raman laser having the same, wherein the narrow-linewidth beam combining module has a first laser, a first fast axis collimating lens, a first wavelength locking device, a second laser, a second fast axis collimating lens, a second wavelength locking device, and a slow axis collimating lens, the wavelengths of the first laser and the second laser are different, one side of the two lasers having PN junctions is opposite to each other and close to each other as much as possible, the light emitted by the first and second lasers is respectively fast-axis collimated by the corresponding fast axis collimating lens and then is wavelength-locked by the respective wavelength locking device to form two fast-axis collimated narrow-linewidth light beams, and the two fast-axis collimated narrow-width light beams are simultaneously incident to the same slow axis collimating lens for slow-axis collimation, and finally form two parallel narrow-linewidth collimated light beams. The multi-wavelength Raman laser is provided with a plurality of narrow-linewidth beam combining modules, collimated light of narrow linewidths emitted from the narrow-linewidth beam combining modules is combined into parallel combined light beams through a beam combining lens, and the combined light beams are converged and imaged to the end face of an output optical fiber through a focusing lens to complete coupling. The structure of the narrow linewidth beam combining module provided by the application enables emergent light to be directly incident into the focusing lens to be coupled into the optical fiber, and the mode that the light beam combination needs to pass through the beam combining lens is eliminated; the structure of the multi-wavelength Raman laser reduces the overall adjustment difficulty of the laser, reduces the use number of optical devices, and enhances the flexibility of the internal structure design of the laser on the premise of ensuring enough stability. However, the invention only provides a specific structure of the laser, and does not solve the problems of heat dissipation and temperature control of the whole system of the laser.

SUMMERY OF THE UTILITY MODEL

To present whole technical problem who closes a bundle system and lack control by temperature change processing and encapsulation difficulty of outside, the utility model provides a beam system is closed to incoherent double-circuit in well infrared quantum cascade laser instrument space, simple structure just closes and restraints effectually, realizes the heat dissipation and the accuse temperature function of quantum cascade laser instrument simultaneously, guarantees the normal work of infrared quantum cascade laser instrument in the double-circuit.

In order to achieve the above purpose, the technical scheme of the utility model is realized as follows: a spatial incoherent double-path beam combining system of a mid-infrared quantum cascade laser comprises a quantum-level laser meter, a heat dissipation device and a laser shell, wherein the quantum-level laser meter and the heat dissipation device are both arranged inside the laser shell, the quantum-level laser meter is arranged on the upper side of the heat dissipation device, and a thermistor of the heat dissipation device is arranged on the quantum-level laser meter.

The quantum level laser meter comprises two groups of optical combination beam modules and a collecting lens, and laser enters the collecting lens after being output by the optical combination beam modules.

The optical beam combining module comprises a laser, a collecting lens and a reflecting mirror, the centers of the laser, the collecting lens and the reflecting mirror are all arranged on the same horizontal line, and the reflecting mirror is matched with the collecting lens; the laser is output by the laser, sequentially passes through the collecting lens and the reflecting mirror and then enters the collecting lens.

The lasers of the two groups of optical combining modules are arranged in parallel.

The laser is a single-tube quantum cascade laser, the collecting lens is a mid-infrared aspheric collimating lens, and the reflecting mirror is a mid-infrared reflecting mirror.

A groove is formed in the laser shell, and the collecting lens, the reflecting mirror and the collecting lens are fixed in the groove.

The heat dissipation device comprises a semiconductor refrigerator and a circulating water cooling device, wherein the semiconductor refrigerator and the circulating water cooling device are sequentially arranged on the lower side of the quantum-grade laser meter.

The semiconductor refrigerator comprises a thermistor, a semiconductor refrigeration group and a control box, wherein the thermistor and the semiconductor refrigeration group are connected with the control box, the thermistor is matched with the laser, and the semiconductor refrigeration group is arranged on the lower side of the quantum-grade laser meter.

The circulating water cooling device comprises a temperature control table and a water cooling machine, wherein the temperature control table is connected with the water cooling machine, and the temperature control table is arranged on the lower side of the semiconductor refrigerator.

The utility model discloses closed the light path of restrainting to space incoherent double-circuit and simplified, the installation of collecting lens, collecting lens and speculum is comparatively convenient, only needs infrared reflector in two aspheric surface collimating lens and two just can reach the purpose of closing the restrainting in the far field, simple structure, and the stack of fine realization double-circuit laser power under the condition of the loss of not considering lens and light beam transmission, when obtaining higher power output, does not change the light beam quality. And simultaneously, the utility model discloses a heat abstractor has set up two sets of heat abstractor, and realization quantum cascade laser that this system can be fine dispels the heat and the accuse temperature function, guarantees the normal work of infrared quantum cascade laser in the double-circuit, and the means that closes the beam system for quantum cascade laser multichannel provides a new design.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the description below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is the light path design diagram of the spatial incoherent two-path beam combining system of the present invention.

Fig. 3 is a structural diagram of the laser housing of the present invention.

Fig. 4 shows the aspheric collimating lens parameters selected for use in the system of the present invention.

Fig. 5 is an output characteristic test chart of the beam combining system of the present invention, (a) is a two-way output characteristic curve of the near field, and (b) is a far field beam combining output characteristic curve.

In the figure, 1 is a quantum level laser meter, 11 is a collecting lens, 12 lasers, 13 is a collecting lens, 14 is a reflecting mirror, 2 is a heat sink, 21 is a thermistor, 22 is a semiconductor refrigerator, 23 is a circulating water cooling device, 3 is a laser housing, and 31 is a groove.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without any creative effort belong to the protection scope of the present invention.

As shown in fig. 1, a spatial incoherent two-path beam combining system of an intermediate infrared quantum cascade laser comprises a quantum-level laser meter 1, a heat dissipation device 2 and a laser housing 3, wherein the quantum-level laser meter 1 and the heat dissipation device 2 are both arranged inside the laser housing 3, the quantum-level laser meter 1 is arranged on the upper side of the heat dissipation device 2, and a thermistor 21 of the heat dissipation device 2 is arranged on the quantum-level laser meter 1. The quantum laser 1 mainly functions to combine a plurality of laser beams, and the heat sink 2 is mainly used to dissipate heat of the quantum laser meter 1.

Specifically, as shown in fig. 2, the quantum level laser meter 1 includes two sets of optical combining modules and a focusing lens 11, and the laser light enters the focusing lens 11 after being output by the optical combining modules. The optical beam combining module comprises a laser 12, a collecting lens 13 and a reflecting mirror 14, the centers of the laser 12, the collecting lens 13 and the reflecting mirror 14 are all arranged on the same horizontal line, the reflecting mirror 14 is matched with the collecting lens 11, and the lasers 12 of the two optical beam combining modules are arranged in parallel; the laser light is output by the laser 12, passes through the collecting lens 13 and the reflecting mirror 14 in sequence, and enters the condensing lens 11. The laser 12 is a single-tube quantum cascade laser, the lasers 12 of the two groups of quantum laser meters 1 are arranged in parallel, and the laser 12 mainly serves to output parallel laser. The collecting lens 13 is a mid-infrared aspheric collimating lens, and the collecting lens 13 mainly functions to convert the input laser light into collimated parallel light. The mirror 14 is a mid-infrared mirror, and its main function is to change the transmission direction of the collimated parallel light, to make the space between the two laser beams in space as small as possible, and to make the output beam pass through the focusing lens 11. As shown in fig. 3, a groove 31 is provided in the laser housing 3, and the collecting lens 13, the reflecting mirror 14, and the condensing lens 11 are fixed in the groove 31. When the ultraviolet curing glue is installed, firstly, the positions of the collecting lens 13, the reflecting mirror 14 and the collecting lens 11 are adjusted to enable laser to be successfully combined, and after the adjustment is completed, the ultraviolet curing glue is injected into the positions below the collecting lens 13, the reflecting mirror 14 and the collecting lens 11 by using the needle tube to ensure that the lenses and the ultraviolet glue have proper contact amount. After the ultraviolet glue is injected, the collecting lens 13, the reflecting mirror 14 and the condensing lens 11 are lowered back to the original height, and the light spot change in the light beam analyzer is observed in real time. And finally, curing the ultraviolet glue by using an ultraviolet lamp with the wavelength of 365 nm, and simultaneously closely monitoring the change of light spots to ensure that the positions of the collecting lens 13, the reflecting mirror 14 and the collecting lens 11 are not shifted in the fixing process.

The heat dissipation device 2 comprises a semiconductor refrigerator 22 and a circulating water cooling device 23, and the semiconductor refrigerator 22 and the circulating water cooling device 23 are sequentially arranged on the lower side of the quantum level laser meter 1. The semiconductor refrigerator 22 comprises a thermistor 21, a semiconductor refrigeration group and a control box, the thermistor 21 and the control box are both connected with the semiconductor refrigeration group, the thermistor 21 is matched with the laser 12, and the semiconductor refrigeration group is arranged on the lower side of the quantum level laser meter 1. Specifically, the thermistor 21 monitors the temperature of the laser 12 in real time, and transmits the measured temperature information to the control box, and when the temperature information transmitted by the thermistor 21 is greater than a set temperature, the control box controls the semiconductor refrigeration unit to be powered on for refrigeration, so as to cool the quantum-level laser meter 1. The circulating water cooling device 23 comprises a temperature control table and a water cooling machine, wherein the temperature control table is connected with the water cooling machine and arranged on the lower side of the semiconductor refrigerator 22. A groove 31 channel is reserved in the temperature control table, and cold water with set temperature can be injected into the groove 31 channel of the temperature control table by the water cooler, so that refrigeration of the temperature control table is realized. The water cooler is a CW-5200 laser water cooler produced by special-area electromechanics, the refrigerating capacity can reach 1400W, the temperature control precision can reach +/-0.3 ℃, and the temperature difference can be controlled to +/-0.1 ℃.

As shown in fig. 4, the lens is a light path medium and far infrared aspheric lens with model 390036 and an antireflection film with model IR3. Effective focal length: 4.0 mm; the design wavelength is 2.5 μm; numerical aperture: 0.56; clear aperture: 5.0 mm; the outer diameter is 6.5 mm; the working distance is 3.05 mm; the center thickness is 2.50 mm. As shown in FIG. 5, the pulse width of the power supply was fixed at 200 ns, the repetition frequency was 10 kHz, and the temperature was controlled at 20 ℃. It was found that the QCL1 threshold current density was 2.21 kA/cm2 and the QCL2 threshold current density was 2.53 kA/cm2. As shown in FIG. 5 (a), in the near field case, the peak power of QCL1 is 39W and the peak power of QCL2 is 34W at 75V. As shown in fig. 5 (b), the peak power after far-field beam combination can reach 65W at 75V, and the beam combination efficiency is 88.8%.

The utility model discloses a space incoherent closes and restraints the requirement of restrainting of closing of realization multichannel mid infrared quantum cascade laser that the system can be fine, relies on in the dimensional design of lens and tube, the utility model discloses realize multichannel output's stack when not changing the light beam quality. And simultaneously, the utility model discloses a set up two sets of heat abstractor in heat abstractor 2, realization quantum cascade laser that this system can be fine dispels the heat and the accuse temperature function, guarantees the normal work of infrared quantum cascade laser in the double-circuit, and the means of closing the beam system for quantum cascade laser multichannel provides a new design.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a spatial incoherent double-path beam combining system of intermediate infrared quantum cascade laser, which is characterized in that, including quantum level laser meter (1), heat abstractor (2) and laser casing (3), quantum level laser meter (1) and heat abstractor (2) all set up inside laser casing (3), quantum level laser meter (1) sets up in heat abstractor (2) upside, thermistor (21) of heat abstractor (2) set up on quantum level laser meter (1).

2. The mid-infrared quantum cascade laser spatial incoherent two-way beam combining system according to claim 1, wherein the quantum level laser meter (1) comprises two sets of optical beam combining modules and a focusing lens (11), and the laser light is output by the optical beam combining modules and enters the focusing lens (11).

3. The spatial incoherent two-beam combining system of the mid-infrared quantum cascade laser according to claim 2, wherein the beam combining module comprises a laser (12), a collecting lens (13) and a reflecting mirror (14), the centers of the laser (12), the collecting lens (13) and the reflecting mirror (14) are all arranged on the same horizontal line, and the reflecting mirror (14) is matched with the collecting lens (11);

the laser is output by the laser (12), and then enters the condensing lens (11) after sequentially passing through the collecting lens (13) and the reflecting mirror (14).

4. The mid-infrared quantum cascade laser spatial incoherent two-way beam combining system according to claim 3, characterized in that the lasers (12) of the two sets of optical beam combining modules are arranged in parallel.

5. The mid-infrared quantum cascade laser spatial incoherent two-way beam combining system according to claim 3 or 4, wherein the laser (12) is a single-tube quantum cascade laser, the collecting lens (13) is a mid-infrared aspheric collimating lens, and the reflecting mirror (14) is a mid-infrared reflecting mirror.

6. The spatial incoherent two-beam combining system of a mid-infrared quantum cascade laser according to claim 5, characterized in that a groove (31) is provided in the laser housing (3), and the collecting lens (13), the reflecting mirror (14) and the condensing lens (11) are all fixed in the groove (31).

7. The spatial incoherent two-path beam combining system of a mid-infrared quantum cascade laser according to claim 6, characterized in that the heat sink (2) comprises a semiconductor refrigerator (22) and a circulating water-cooling device (23), and the semiconductor refrigerator (22) and the circulating water-cooling device (23) are sequentially arranged on the lower side of the quantum level laser meter (1).

8. The spatial incoherent two-path beam combining system of the mid-infrared quantum cascade laser device according to claim 7, wherein the semiconductor refrigerator (22) comprises a thermistor (21), a semiconductor refrigerating set and a control box, the thermistor (21) and the semiconductor refrigerating set are both connected with the control box, the thermistor (21) is matched with the laser device (12), and the semiconductor refrigerating set is arranged on the lower side of the quantum-level laser meter (1).

9. The spatial incoherent two-path beam combining system of the mid-infrared quantum cascade laser according to claim 7 or 8, characterized in that the circulating water cooling device (23) comprises a temperature control table and a water cooling machine, the temperature control table is connected with the water cooling machine, and the temperature control table is arranged at the lower side of the semiconductor cooling machine (22).