Packaging structure, packaging method and application of lens-free coaxial TO-CAN collimating laser

Abstract

The invention discloses a packaging structure, a packaging method and application of a lens-free coaxial TO-CAN collimating laser. The packaging structure comprises a TO-CAN base, a TEC temperature controller, a laser chip, a coupling heat sink gasket and a rotary parabolic concave reflector. The rotary parabolic concave reflector is arranged on one side of the coupling heat sink gasket, the laser chip is arranged on the upper surface of the coupling heat sink gasket, and a light emitting point of the laser chip coincides with a focus of the rotary parabolic concave reflector; according to the invention, a traditional collimating lens is canceled, and a light beam is reflected to form a parallel light beam by using the rotary parabolic concave reflector, so that the interference effect is reduced; when two or more laser chips with different wavelengths are arranged in one TO-CAN, two or more different gases can be detected at the same time in a complex gas environment in which different gases are mixed, so that the universality of the laser gas sensor is remarkably improved; meanwhile, the requirement for subsequent optical adjustment is reduced, assembly limitation is remarkably reduced, and the assembly process is simplified.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detection technology, and in particular to a packaging structure, a packaging method and an application of a lens-free coaxial TO-CAN collimating laser. Background Art

[0002] At present, in the field of photoelectric detection instruments, most laser light sources and detector devices come from the optical fiber communication industry. Due to the vigorous development of the optical communication industry, laser light sources and detectors can be mass-produced, which not only improves production quality but also reduces production costs. Since the design of these laser light sources and detector devices is to facilitate the optical coupling of these components and optical fibers, most laser and detector components adopt the design form of coaxial TO-CAN, and these coaxial TO-CAN components have also been widely used because of their large quantities and low costs. However, when the coaxial TO-CAN component using a collimating lens is used in the sensor field, the reflected light from the lens surface will generate interference noise on the output beam of the laser after entering the resonator of the laser. Especially in laser gas detection, since the laser wavelength needs to be modulated, the interference noise generated by the reflected light on the lens surface and the beam of the laser resonant cavity will form interference background noise in the detection signal of the detector. This interference noise changes with the change of ambient temperature, so at different ambient temperatures, it will affect the accuracy of the measured gas concentration.

[0003] In addition, the existing coaxial packaging structure requires different collimating lenses and focusing lenses for lasers and detectors of different wavelengths; in the simultaneous detection of multiple gases in a mixed gas space, it is necessary to use separate components of lasers and detectors that match different wavelengths for measurement. The existing set of coaxial packaging structures cannot realize the simultaneous detection of multiple gases in a mixed gas space, especially it cannot be applied to gas monitoring in complex environments, and its versatility is not strong. In the Chinese invention patent with announcement number CN111244747B and patent name A coaxial laser TO-CAN, a coaxial laser TO-CAN and its preparation method for reducing such noise are introduced. The core of this method is to subtract or eliminate the reflection at the center of the lens. However, its packaging process is complicated, the processing cost is high, the overall space occupied is also large, and the miniaturization design needs to be optimized.

[0004] Therefore, how to design a new type of laser to facilitate the application of lens-free design in laser gas detection applications, especially laser gas monitoring in complex environments, is a technical problem that urgently needs to be solved. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned prior art, one of the objects of the present invention is to provide a packaging structure of a lensless coaxial TO-CAN collimated laser, which eliminates the traditional collimating lens and avoids the interference noise caused by the reflection of the collimating lens surface. By using a rotating parabolic concave reflector, the light beam is reflected to form a parallel light beam, which reduces the interference effect and significantly improves the measurement accuracy, especially in precision measurement applications such as gas concentration detection.

[0006] The second purpose of the present invention is to provide a packaging method for a packaging structure of a lensless coaxial TO-CAN collimated laser. The method achieves efficient assembly and ensures product quality and consistency by optimizing processes, reducing assembly time, flexible adjustment mechanisms, and rapidly curing materials, thereby providing strong support for the application of lasers.

[0007] The third object of the present invention is to provide a dual-wavelength or multi-wavelength laser including the packaging structure of the above-mentioned lensless coaxial TO-CAN collimated laser, further realizing the simultaneous detection of complex gas environments of two or more different gases, and significantly improving the versatility of the laser.

[0008] On the other hand, the present invention can also utilize the principle of reversible optical path. In other optional implementations, the packaging structure of the present invention is applied to the detector packaging to replace the converging lens of the detector.

[0009] One of the purposes of the present invention is achieved through the following technical solutions:

[0010] A packaging structure of a lens-free coaxial TO-CAN collimating laser, comprising a TO-CAN base and a TEC temperature controller, a laser chip, a coupling heat sink gasket, and a rotating parabolic concave reflector arranged on the TO-CAN base; the TEC temperature controller and the coupling heat sink gasket are stacked in sequence on the upper surface of the TO-CAN base; the rotating parabolic concave reflector is arranged on one side of the coupling heat sink gasket, the laser chip is arranged on the upper surface of the coupling heat sink gasket, and the light emitting point of the laser chip or the top of the light cone emitted by the laser chip is aligned and overlapped with the focus of the rotating parabolic concave reflector; the off-axis angle between the center line of the light cone and the parallel light beam reflected by the rotating parabolic concave reflector is less than or equal to 90°;

[0011] The divergent light beam emitted by the laser chip is reflected by the rotating parabolic concave reflector to form a collimated light beam parallel to its optical axis.

[0012] As a further illustration of the above solution, the rotating parabolic concave reflector is a concave rotating reflector formed by rotating the parabola 180° around the central axis with the main axis of the parabola as the central axis.

[0013] As a further illustration of the above scheme, the rotating parabolic concave reflector includes a reflector base and a concave mirror surface integrally formed on the reflector base; the rotating parabolic concave reflector is formed by injection molding or by stamping of mirror steel; the concave mirror surface is coated with a reflective film; the reflector base is provided with a connecting hole for mounting it on the coupling heat sink gasket.

[0014] As a further illustration of the above solution, an avoidance gap is provided inside the rotating parabolic concave reflector, and the laser chip extends into the avoidance gap and aligns its light-emitting point with the focus of the rotating parabolic concave reflector.

[0015] As a further illustration of the above solution, the off-axis angle between the center line of the light cone and the parallel light beam reflected by the rotating parabolic concave reflector is 90°.

[0016] As a further illustration of the above solution, the laser chip is one of a COC laser chip, a DFB laser chip, an ICL laser chip or a QCL laser chip.

[0017] As a further illustration of the above scheme, the TEC temperature controller and the coupling heat sink gasket are respectively adhered to the upper surface of the TO-CAN base by silver glue; the laser chip is bonded to the coupling heat sink gasket, and the light output point of the laser chip or the top of the light cone emitted by the laser chip is aligned and overlapped with the focus of the rotating parabolic concave reflector.

[0018] The second object of the present invention is achieved by the following technical solutions:

[0019] A packaging method for the packaging structure of the lensless coaxial TO-CAN collimated laser as described above comprises the following steps:

[0020] Step 1: Fix the TO-CAN base and determine the light source reference plane of the laser;

[0021] Step 2: Install the TEC temperature controller, the coupling heat sink gasket, and the laser chip on the TO-CAN base in step 1 respectively, and power on the TEC temperature controller and the laser chip;

[0022] Step 3: Install the rotating parabolic concave reflector on one side of the coupling heat sink pad through a 6-dimensional adjustment frame, and adjust the rotating parabolic concave reflector relative to the light-emitting point position of the laser chip in step 2 so that its focus is aligned with the light-emitting point of the laser chip;

[0023] Step 4: fix the rotational parabolic concave reflector adjusted in step 3 to the coupling heat sink gasket, and adjust the optical path;

[0024] Step 5: Connect the TO-CAN base, TEC temperature controller, coupled heat sink gasket, laser chip, and rotating parabolic concave reflector after the optical path adjustment in step 4, and cover the entire exterior with a cap with an inclined window to complete the packaging.

[0025] As a further illustration of the above scheme, in step 4, a mounting groove for placing the rotational parabolic concave reflector is recessed on the coupling heat sink gasket, and the rotational parabolic concave reflector is fixed to the coupling heat sink gasket by UV adhesive.

[0026] The third object of the present invention is achieved by the following technical solutions:

[0027] An application of a packaging structure of a lensless coaxial TO-CAN collimating laser in a dual-wavelength or multi-wavelength laser, comprising the packaging structure of the lensless coaxial TO-CAN collimating laser as described above, prepared by a packaging method corresponding to the packaging structure of the lensless coaxial TO-CAN collimating laser described above;

[0028] Two or more of the rotating parabolic concave reflectors are respectively arranged on both sides of the coupling heat sink pad, and two or more of the laser chips are adjacent and the light exit points are arranged on the coupling heat sink pad in reverse, located between or on the periphery of the two or more rotating parabolic concave reflectors; and the light exit point of the laser chip or the top of the light cone emitted by the laser chip is aligned and overlapped with the focus of the corresponding rotating parabolic concave reflector.

[0029] As a further explanation of the above scheme, in the step 2, two or more of the rotating parabolic concave reflectors are respectively arranged on two sides or multiple sides of the coupling heat sink gasket, and two or more of the laser chips are respectively arranged on each side, and the top of the light cone of the light beam outlet point of the two or more laser chips is aligned and overlapped with the focus of the corresponding rotating parabolic concave reflector.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects:

[0031] (1) The present invention eliminates the traditional collimating lens, avoiding the interference noise caused by the reflection of the collimating lens surface. By using a rotating parabolic concave reflector, the light beam forms a parallel light beam after reflection, reducing the interference effect, thereby significantly improving the measurement accuracy, especially in precision measurement applications such as gas concentration detection;

[0032] In addition, the design of the parabolic concave reflector makes the present invention have good adaptability to laser light sources of different wavelengths; therefore, the same reflection collimation system can be used for lasers of different wavelengths, which is beneficial for application in different gas detections, enhances the versatility of the system, and is applicable to a variety of lasers, such as COC laser chips, DFB laser chips, etc.

[0033] Furthermore, since the reflector surface does not absorb the beam energy and the concave design can effectively reflect the beam, the collimation structure is particularly suitable for the application of high-power and ultra-high-power lasers, avoiding the performance damage of traditional lenses due to thermal effects; the present invention can maintain stable optical performance and ensure the safe and efficient operation of the laser;

[0034] (2) The coupling packaging process of the present invention makes the packaging process highly compact and efficient as a whole by simplifying steps, integrated design, precise alignment, efficient adjustment mechanism and rapid fixation. Specifically, the various auxiliary positioning devices of the traditional lens installation are eliminated, and the rotating parabolic concave reflector is positioned by using a precise optical path adjustment device and a 6-dimensional adjustment frame, so that fine-tuning can be performed quickly during installation, which not only saves debugging time, but also enables accurate alignment during the initial assembly, reducing subsequent modification work. The reflector is fixed with UV glue, which greatly shortens the curing time and improves the assembly speed. The positioning of the components is simplified, and the key components can be directly fixed after the optical path adjustment, avoiding multiple disassembly and repeated adjustment processes. On the other hand, each modular component can be processed independently, reducing the complexity caused by interference between components.

[0035] (3) The present invention integrates the TEC temperature controller, the coupled heat sink gasket, the laser chip and the parabolic concave reflector on the TO-CAN base. The compact layout reduces the spacing between the components, making the overall volume smaller, facilitating installation and integration in a limited space, and reducing the optical errors between the components. Furthermore, due to the direct alignment between the parabolic concave reflector and the laser chip, no additional auxiliary positioning tools or complicated adjustment steps are required during the entire packaging process, thus avoiding the common focus and axis alignment errors in the traditional lens installation process. At the same time, the compact structure also improves the connectivity of the packaging process, avoiding unnecessary repeated steps, and ensuring that the entire packaging process is efficient and smooth.

[0036] (4) The present invention improves the collimation of the light beam by ensuring that the laser light source is directly aligned with the focus of the parabolic concave reflector, reduces the need for subsequent optical adjustments, and significantly simplifies the assembly process. Compared with the traditional technology that requires multiple focusing, adjustment, and lens fixing processes, the design of the present invention greatly reduces the reliance on auxiliary equipment and reduces the complexity of installation. Also, due to the lack of the complexity of focusing and axial alignment, the assembly process becomes more intuitive and simple, reducing the skill requirements of the operator and reducing assembly errors caused by misoperation. Therefore, not only the assembly efficiency is greatly improved, but also the stability of product quality is ensured;

[0037] (5) The present invention can also use the same packaging process to prepare a dual-collimated beam and dual-wavelength or multi-collimated multi-wavelength laser, and integrate more than two COC laser chips with different wavelengths on the same TO-CAN base, so that the system can detect multiple gases at the same time, significantly improving the application range of the laser, and can meet the needs of different gas detection, especially in gas monitoring in complex environments; optimize the absorption characteristics of specific gases, and improve the sensitivity and accuracy of detection;

[0038] Furthermore, lasers of different wavelengths can be optimized for the absorption characteristics of specific gases, and can meet the detection needs of multiple gases mixed in the same space at the same time, and can realize the simultaneous detection of more than two different gases, significantly improving the versatility and convenience of lasers; by comparing the gas absorption characteristics at two wavelengths, this comparative analysis can effectively reduce background noise and interference, improve the signal-to-noise ratio, and make the detection results more reliable;

[0039] On the other hand, integrating dual-wavelength or multi-wavelength lasers in the same package can significantly simplify system design and reduce the need for external components, thereby reducing the complexity of the overall system. The compact design also reduces the requirements for installation space. Two or more laser chips operate on the same platform and share the same thermal management system, which can more effectively control temperature changes, thereby reducing performance instability caused by temperature fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of the overall structure of the packaging structure of the lens-free coaxial TO-CAN collimating laser according to Example 1 of the present invention;

[0041] Figure 2 It is a schematic diagram of the overall structure of the rotating parabolic concave reflector of the packaging structure of the lensless coaxial TO-CAN collimating laser of Embodiment 1-2 of the present invention;

[0042] Figure 3 This is a schematic diagram of the overall structural cross-sectional state of the packaging structure of the lens-free coaxial TO-CAN collimating laser according to Example 1 of the present invention;

[0043] Figure 4 for Figure 3 A schematic diagram of the enlarged local structure at center A;

[0044] Figure 5 A schematic diagram of the optical path trajectory of the laser collimated light beam which is perpendicular to the optical axis of the original divergent light beam after being collimated by the rotating parabolic concave reflector of the packaging structure of the lensless coaxial TO-CAN collimated laser of Example 1-2 of the present invention;

[0045] Figure 6 A schematic diagram of the assembly state of the rotating parabolic concave reflector of the dual-wavelength laser applied to the packaging structure of the lensless coaxial TO-CAN collimating laser of Example 2 of the present invention;

[0046] Figure 7 A schematic diagram of the assembly state of the rotating parabolic concave reflector of the four-wavelength laser applied to the packaging structure of the lensless coaxial TO-CAN collimating laser of Example 3 of the present invention;

[0047] Figure 8 This is a schematic diagram of the packaging structure of a detector prepared based on the packaging structure of the lens coaxial TO-CAN collimated laser of Example 1 and using the principle of reversible optical path.

[0048] In the figure:

[0049] 1. TO-CAN base; 2. TEC temperature controller; 3. Laser chip; 31. Light output point; 4. Coupling heat sink gasket; 5. Rotating parabolic concave reflector; 51. Reflector base; 511. Connection hole; 52. Concave mirror surface; 53. Avoidance gap;

[0050] F. The focus of the rotating parabolic concave reflector;

[0051] L1, the parabola principal axis of the rotating parabolic concave reflector;

[0052] L2, center line of light cone;

[0053] α, the off-axis angle between the center line of the light cone and the parallel light beam after reflection by the rotating parabolic concave reflector. DETAILED DESCRIPTION

[0054] In order to facilitate the understanding of the present invention, the technical solutions and advantages of the invention are further described in detail below in conjunction with the accompanying drawings and embodiments. The specific structure and characteristics of the present invention are described below by way of example, which should not constitute any limitation to the present invention. At the same time, any of the following technical features mentioned (including implicit or disclosed), as well as any technical features directly displayed or implied in the figure, can continue to be arbitrarily combined or deleted between these technical features, so as to form more other embodiments that may not be directly or indirectly mentioned in the present invention. The preferred embodiments of the present invention are given in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0055] Example 1

[0056] like Figure 1-5 As shown, this embodiment 1 provides a packaging structure of a lensless coaxial TO-CAN collimated laser, including a TO-CAN base 1 and a TEC temperature controller 2, a laser chip 3, a coupling heat sink gasket 4, and a rotating parabolic concave reflector 5 arranged on the TO-CAN base 1; the TEC temperature controller 2 and the coupling heat sink gasket 4 are stacked in sequence on the upper surface of the TO-CAN base 1; the rotating parabolic concave reflector 5 is arranged on one side of the coupling heat sink gasket 4, the laser chip 3 is arranged on the upper surface of the coupling heat sink gasket 4, and the light emitting point 31 of the laser chip 3 or the top of the light cone emitted by the laser chip 3 is aligned and overlapped with the focus F of the rotating parabolic concave reflector; the off-axis angle α between the center line of the light cone and the parallel light beam reflected by the rotating parabolic concave reflector is less than or equal to 90°;

[0057] The divergent light beam emitted by the laser chip 3 is reflected by the rotating parabolic concave reflector 5 to form a collimated light beam parallel to its optical axis.

[0058] In this embodiment, the light beam emitted by the laser chip is generally a light cone with an elliptical cross section, and the off-axis angle between the center line L2 of the light cone and the parallel light beam after reflection is in the range of 85-90°. In this way, a rotating parabolic concave reflector can be used to make the light cone reflect to form a parallel light beam parallel to the main axis of the rotating parabolic concave reflector; when the off-axis angle gradually decreases from 90°, the diameter of the reflected light spot also gradually decreases. By using this physical property, the center line of the laser light cone and the collimated light beam are adjusted to form an angle less than 90°, and the diameter of the light spot in the fast axis direction can be reduced, so as to collimate the divergent light beam with an elliptical cross section into a parallel light beam with a nearly circular cross section. In this embodiment, it is preferred that the off-axis angle α between the center line of the light cone and the parallel light beam after reflection by the rotating parabolic concave reflector is 90°.

[0059] The structure of the rotating parabolic concave reflector 5 is further described. The rotating parabolic concave reflector 5 is a concave rotating reflector formed by rotating the parabola 180° around the main axis L1 of the parabola as the central axis.

[0060] In this embodiment, the coupled heat sink gasket has two main functions. The first is to introduce the heat emitted by the laser chip into the TEC temperature controller under the gasket through the coupled heat sink gasket; the second function is to accurately locate the relative position of the concave reflector and the light outlet of the laser chip, that is, to ensure that the laser light source outlet is placed at the focus of the parabolic concave reflector.

[0061] In this embodiment, the light emitting point 31 of the laser chip 3 or the top of the light cone emitted by the laser chip 3 is aligned and overlapped with the focus F of the rotating parabolic concave reflector; this means that the light emitting point 31 and the focus F are in the same plane and on the same straight line and are adjacent to each other.

[0062] As a further preferred embodiment, the rotating parabolic concave reflector 5 includes a reflector base 51 and an inner concave mirror surface 52 integrally formed on the reflector base 51; the rotating parabolic concave reflector 5 is formed by injection molding or by stamping of mirror steel; the inner concave mirror surface 52 is plated with a reflective film; the reflector base 51 is provided with a connecting hole 511 for mounting it on the coupling heat sink pad 4. In this embodiment, the rotating parabolic concave reflector is stamped from a mirror steel material with a small thermal expansion coefficient, and has better stability; and a reflective film protective layer is plated on the reflective surface so that the reflector can adapt to the influence of various environmental changes, and the present invention does not limit the material of the reflective film.

[0063] As a further preferred embodiment, the rotating parabolic concave reflector is provided with an avoidance notch 53, and the laser chip 3 extends into the avoidance notch 53 and aligns its light-emitting point 31 with the focus of the rotating parabolic concave reflector. The advantage of this design is that the rotating parabolic concave reflector and the laser chip can also limit each other, which is conducive to the alignment packaging connection of the connection hole.

[0064] As a further preferred embodiment, the laser chip 3 is one of a COC laser chip, a DFB laser chip, an ICL laser chip or a QCL laser chip. In this embodiment, the design of the parabolic concave reflector enables the present invention to have good adaptability to laser light sources of different wavelengths; therefore, the same reflection collimation system can be used for lasers of different wavelengths, which is beneficial for application in different gas detections, enhances the versatility of the system, and is applicable to a variety of lasers, such as COC laser chips, DFB laser chips, etc., and can meet the detection requirements of a variety of gases.

[0065] As a further preferred embodiment, the TEC temperature controller 2 and the coupling heat sink gasket 4 are respectively adhered to the upper surface of the TO-CAN base 1 by silver glue; the laser chip 3 is bonded to the coupling heat sink gasket 4, and the light emitting point of the laser chip 3 or the top of the light cone emitted by the laser chip 3 is aligned and overlapped with the focus F of the rotating parabolic concave reflector.

[0066] The present invention integrates a TEC temperature controller, a coupled heat sink gasket, a laser chip and a parabolic concave reflector on a TO-CAN base. The compact layout reduces the spacing between components, making the overall volume smaller, facilitating installation and integration in a limited space, and reducing the optical errors between components. Furthermore, due to the direct alignment between the parabolic concave reflector and the laser chip, no additional auxiliary positioning tools or complicated adjustment steps are required in the entire packaging process, thus avoiding the common focus and axis alignment errors in the traditional lens installation process. At the same time, the compact structure also improves the connectivity of the packaging process, avoids unnecessary repeated steps, and ensures that the entire packaging process is efficient and smooth.

[0067] The packaging method of the packaging structure of the lensless coaxial TO-CAN collimated laser of the present embodiment 1 comprises the following steps:

[0068] Step 1: Fix the TO-CAN base 1 and determine the light source reference plane of the laser;

[0069] Specifically, during the packaging process, the TO-CAN base ensures that its plane serves as the reference plane of the laser light source. Determining the reference positioning is an important prerequisite for achieving high-precision alignment and can reduce errors in subsequent adjustments.

[0070] In this step, the TO-CAN base 1 can be fixed by a device with an optical path adjustment function to better determine the light source reference plane of the laser. The optical path adjustment device can adopt a device with corresponding functions in the prior art, which will not be described here. It can be implemented as long as it can achieve the beneficial effects of the present invention.

[0071] Step 2: respectively install the TEC temperature controller 2, the coupling heat sink gasket 4, and the laser chip 3 on the TO-CAN base 1 of step 1, and power on the TEC temperature controller 2 and the laser chip 3;

[0072] Specifically, in this step, first, a TEC temperature controller is glued to the plane of the TO-can base with silver glue, then a coupling heat sink gasket is glued to the TEC with silver glue, and then the COC chip is bonded to the set position of the coupling heat sink gasket; the four probes of the special tooling are used to power on the TEC and COC laser chip respectively, so that the laser can emit laser normally.

[0073] Step 3: Install the rotating parabolic concave reflector 5 on one side of the coupling heat sink pad 4 through a 6-dimensional adjustment frame, and adjust the rotating parabolic concave reflector 5 relative to the light-emitting point position of the laser chip 3 in step 2 so that its focus is aligned with the light-emitting point of the laser chip 3;

[0074] Specifically, in this step, a parabolic concave reflector is placed at the position set by the coupling heat sink pad using a 6-dimensional adjustment frame, and the position of the concave reflector relative to the beam outlet of the laser is fine-tuned until the collimated beam spot meets the preset requirements; and in this step,

[0075] Step 4: Fix the rotating parabolic concave reflector 5 adjusted in step 3 to the coupling heat sink gasket 4, and adjust the optical path; further, in step 4, a mounting groove for placing the rotating parabolic concave reflector 5 is recessed on the coupling heat sink gasket 4, and the rotating parabolic concave reflector 5 is fixed to the coupling heat sink gasket 4 by UV glue.

[0076] At the same time, a mid-infrared beam analyzer is used to detect the adjusted optical path and determine whether it meets the preset requirements.

[0077] Step 5: After the optical path adjustment in step 4, the TO-CAN base 1, TEC temperature controller 2, coupling heat sink gasket 4, laser chip 3, and rotating parabolic concave reflector 5 are connected by wires and pins as a whole, and a cap with an inclined window is installed on the whole outside to complete the packaging.

[0078] Specifically, after the optical path is adjusted, the TO-CAN base is moved to the wire bonding station, and the laser on the COC and the connection wires of the TEC are connected to the pins of the TO-CAN with gold wires; finally, a cap with an inclined window (not shown in the figure) is covered on the TO-CAN base to protect the laser chip. In this embodiment, the cap with an inclined window can be a transmissive inclined window that is inclined outward in the vertical direction and is used for light transmission. The inclination angle and direction can be set according to the packaging requirements, as long as it can achieve the beneficial effects of the present invention.

[0079] The coupling packaging process of the present invention makes the packaging process as a whole highly compact and efficient by simplifying steps, integrating design, precise alignment, efficient adjustment mechanism and rapid fixation; specifically, a variety of auxiliary positioning devices for traditional lens installation are eliminated, and a precise optical path adjustment device and a 6-dimensional adjustment frame are used to position the rotating parabolic concave reflector, so that fine-tuning can be performed quickly during installation, which not only saves debugging time, but also enables accurate alignment during the initial assembly, reducing subsequent modification work; UV glue is used to fix the reflector, so that the curing time is greatly shortened and the assembly speed is improved; the positioning of the components is simplified, and the key components can be directly fixed after the optical path adjustment, avoiding multiple disassembly and repeated adjustment processes; on the other hand, each modular component can be processed independently, reducing the complexity caused by interference between components.

[0080] The present invention ensures that the laser light source is directly aimed at the focus of the parabolic concave reflector, thereby improving the collimation of the light beam, reducing the need for subsequent optical adjustments, and significantly simplifying the assembly process. Compared with the traditional technology that requires multiple focusing, adjustment, and lens fixing processes, the design of the present invention greatly reduces dependence on auxiliary equipment and reduces installation complexity. Also, due to the lack of complexity in aligning the focus and axis centerline, the assembly process becomes more intuitive and simple, reducing the skill requirements of the operator and reducing assembly errors caused by misoperation. Therefore, not only the assembly efficiency is greatly improved, but also the stability of product quality is ensured.

[0081] It should be noted that the present invention also includes other elements such as temperature measuring resistors (not shown in the drawings) that meet the functions of the laser, which will not be elaborated in the present invention.

[0082] Example 2

[0083] like Figure 2 , 5 -6, this embodiment 2 provides a packaging structure of a lensless coaxial TO-CAN collimated laser for application in dual-wavelength lasers. The difference between this embodiment 2 and embodiment 1 is that the two rotating parabolic concave reflectors 5 are respectively arranged on both sides of the coupling heat sink gasket 4, and the two laser chips 3 are adjacent and the light emitting points are arranged inversely on the coupling heat sink gasket 4, located between the two rotating parabolic concave reflectors 5; and the light emitting point of the laser chip 3 or the top of the light cone emitted by the laser chip 3 is aligned and overlapped with the focus F of the corresponding rotating parabolic concave reflector.

[0084] The difference between the packaging method of this embodiment 2 and that of embodiment 1 is that in the step 3, the rotating parabolic concave reflector 5 is installed on one side of the coupling heat sink gasket 4 in sequence, and the rotating parabolic concave reflector 5 is adjusted relative to the light-emitting point position of the laser chip 3 in the step 2 so that its focus is aligned with the light-emitting point of the laser chip 3, or two sets of 6-dimensional adjustment frames, mid-infrared beam analyzers and other instruments are used to perform the operations synchronously according to actual needs.

[0085] Therefore, in this embodiment 2, two COC laser chips with different wavelengths can be installed on the same TO-CAN base 1 at the same time to make a dual-collimated beam and dual-wavelength laser. To be further refined, the two COC laser chips with different wavelengths are placed "back to back" on the coupling heat sink gasket, and the light emission directions of the two COC lasers are set to opposite directions of 180° to each other. Then, two micro-rotating parabolic concave mirrors are respectively set in the light emission direction of the COC laser, and the focal points of the two micro-rotating parabolic concave mirrors are respectively set at the light outlets of the two COC lasers. In this way, on the same TO-CAN base, two COC laser chips with different wavelengths can be installed at the same time to make a dual-collimated beam and dual-wavelength laser.

[0086] The dual collimated beam and dual-wavelength laser of the present embodiment 2 integrates two COC laser chips of different wavelengths on the same TO-CAN base 1, so that the system can detect multiple gases at the same time, significantly improving the application range of the laser, and can meet the needs of different gas detection, especially in gas monitoring in complex environments; optimize the absorption characteristics of specific gases, and improve the sensitivity and accuracy of detection; at the same time, lasers of different wavelengths can be optimized for the absorption characteristics of specific gases, and improve the sensitivity and accuracy of detection;

[0087] Furthermore, dual-wavelength lasers can compare the gas absorption characteristics at two wavelengths. This comparative analysis can effectively reduce background noise and interference, improve the signal-to-noise ratio, and make the detection results more reliable;

[0088] On the other hand, the integration of dual-wavelength lasers in the same package can significantly simplify system design and reduce the need for external components, thereby reducing the complexity of the overall system. The compact design also reduces the requirements for installation space. The two laser chips 3 operate on the same platform and share the same thermal management system, which can more effectively control temperature changes, thereby reducing performance instability caused by temperature fluctuations.

[0089] Example 3

[0090] Similarly, the lensless coaxial TO-CAN packaging structure of the present invention can also be installed with three or more laser chips to prepare a multi-wavelength laser according to the type of detected gas and detection requirements.

[0091] Taking a four-wavelength laser as an example, four COC laser chips can be arranged at the same time, so that they are distributed in a "cross" shape around the four rotating parabolic concave mirrors, such as Figure 7 As shown, a multi-wavelength laser is prepared, which enables the system to detect more gases at the same time, significantly improving the application range of laser detection of multiple gases and adapting to the complex environment of multiple gas detection.

[0092] like Figure 8 As shown, it should be noted that the lensless coaxial TO-CAN packaging structure and packaging process of the present invention, in addition to the single-wavelength collimated laser and the dual-collimated beam and dual-wavelength laser mentioned in the aforementioned content, can also utilize the reversible principle of optical path. In other optional embodiments, the packaging structure of the present invention is used to replace the converging lens of the detector, that is, the photosensitive surface of the detector is placed at the focus of the rotating parabolic concave mirror. The collimation system can directly converge a beam of incident light parallel to the TO-CAN optical axis onto the photosensitive surface of the detector.

[0093] Therefore, the lensless coaxial TO-CAN packaging structure of the present invention can widely adapt to different optical requirements. By directly focusing a beam of incident light parallel to the TO-CAN optical axis onto the photosensitive surface of the detector, the light receiving efficiency of the detector is improved. It can be quickly switched according to different application requirements without the need to design different optical elements for each application. In gas monitoring equipment, the sensitivity of the detector is improved to ensure a rapid response to trace gases.

[0094] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. For ordinary technicians in this field, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A packaging structure of a lensless coaxial TO-CAN collimated laser, characterized in that: It comprises a TO-CAN base and a TEC temperature controller, a laser chip, a coupling heat sink gasket, and a rotating parabolic concave reflector arranged on the TO-CAN base; the TEC temperature controller and the coupling heat sink gasket are stacked in sequence on the upper surface of the TO-CAN base; the rotating parabolic concave reflector is arranged on one side of the coupling heat sink gasket, the laser chip is arranged on the upper surface of the coupling heat sink gasket, and the light emitting point of the laser chip or the top of the light cone emitted by the laser chip is aligned and overlapped with the focus of the rotating parabolic concave reflector; the off-axis angle between the center line of the light cone and the parallel light beam reflected by the rotating parabolic concave reflector is less than or equal to 90°; The divergent light beam emitted by the laser chip is reflected by the rotating parabolic concave reflector to form a collimated light beam parallel to its optical axis.

2. The packaging structure of the lensless coaxial TO-CAN collimated laser according to claim 1, characterized in that: The rotating parabola concave reflector is a concave rotating reflector formed by rotating the parabola 180° around the central axis with the main axis of the parabola as the central axis.

3. The packaging structure of the lensless coaxial TO-CAN collimated laser according to claim 2, characterized in that: The rotating parabolic concave reflector includes a reflector base and an inner concave mirror surface integrally formed on the reflector base; the rotating parabolic concave reflector is formed by injection molding or by stamping of mirror steel; the inner concave mirror surface is coated with a reflective film; the reflector base is provided with a connecting hole for mounting it on the coupling heat sink gasket.

4. The packaging structure of the lensless coaxial TO-CAN collimated laser according to claim 3, characterized in that: The laser chip is one of a COC laser chip, a DFB laser chip, an ICL laser chip or a QCL laser chip.

5. The packaging structure of the lensless coaxial TO-CAN collimated laser according to claim 3, characterized in that: The TEC temperature controller and the coupling heat sink gasket are respectively adhered to the upper surface of the TO-CAN base by silver glue; the laser chip is bonded to the coupling heat sink gasket, and the light emitting point of the laser chip or the top of the light cone emitted by the laser chip is aligned and overlapped with the focus of the rotating parabolic concave reflector.

6. A packaging method for the packaging structure of the lensless coaxial TO-CAN collimated laser according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Fix the TO-CAN base and determine the light source reference plane of the laser; Step 2: Install the TEC temperature controller, the coupling heat sink gasket, and the laser chip on the TO-CAN base in step 1 respectively, and power on the TEC temperature controller and the laser chip; Step 3: Install the rotating parabolic concave reflector on one side of the coupling heat sink pad through a 6-dimensional adjustment frame, and adjust the rotating parabolic concave reflector relative to the light-emitting point position of the laser chip in step 2 so that its focus is aligned with the light-emitting point of the laser chip; Step 4: fix the rotational parabolic concave reflector adjusted in step 3 to the coupling heat sink gasket, and adjust the optical path; Step 5: Connect the TO-CAN base, TEC temperature controller, coupled heat sink gasket, laser chip, and rotating parabolic concave reflector after the optical path adjustment in step 4, and cover the entire exterior with a cap with an inclined window to complete the packaging.

7. The packaging method of the packaging structure of the lensless coaxial TO-CAN collimated laser according to claim 6, characterized in that: In step 4, a mid-infrared beam analyzer is used to detect the adjusted optical path and determine whether it meets the preset requirements.

8. The packaging method of the packaging structure of the lensless coaxial TO-CAN collimated laser according to claim 6, characterized in that: In the step 4, a mounting groove for placing the rotational parabolic concave reflector is recessed on the coupling heat sink gasket, and the rotational parabolic concave reflector is fixed on the coupling heat sink gasket by UV adhesive.

9. Application of a packaging structure of a lensless coaxial TO-CAN collimating laser in a dual-wavelength or multi-wavelength laser, comprising the packaging structure of the lensless coaxial TO-CAN collimating laser as claimed in any one of claims 1 to 5, prepared by the packaging method of the packaging structure of the lensless coaxial TO-CAN collimating laser as claimed in any one of claims 6 to 8; It is characterized in that Two or more of the rotating parabolic concave reflectors are respectively arranged on two sides or multiple sides of the coupling heat sink pad, and two or more of the laser chips are adjacent and the light exit points are arranged on the coupling heat sink pad in the opposite direction, located between or on the periphery of the two or more rotating parabolic concave reflectors; and the light exit point of the laser chip or the top of the light cone emitted by the laser chip is aligned and overlapped with the focus of the corresponding rotating parabolic concave reflector.

10. Application of the packaging structure of the lensless coaxial TO-CAN collimated laser as claimed in claim 9 in dual-wavelength or multi-wavelength lasers, characterized in that: In the step 3, two or more of the rotating parabolic concave reflectors are respectively arranged on two or more sides of the coupling heat sink gasket, and two or more of the laser chips are respectively arranged on two or more sides, and the light beam exit points of the two or more laser chips are aligned and overlapped with the focal points of the corresponding rotating parabolic concave reflectors.

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