High-performance non-magnetic 795nm collimation laser light source

Abstract

The invention relates to the technical field of lasers, in particular to a high-performance non-magnetic 795nm collimation laser light source which comprises a laser body, and the laser body comprises a 795nm Vcsel laser chip, a thermistor, a capacitor, a ceramic substrate, a thermoelectric cooler TEC, a primary refraction prism, a secondary refraction prism, an Al alloy base, a collimation lens, a lens base, a non-magnetic tube shell and a cover plate. The invention aims to realize the following technical effects: a non-magnetic packaging scheme is provided, so that the magnetic intensity of a device is less than 1nT, and an application scene with strict requirements on a magnetic field environment is met; a microminiature laser is designed, the overall device size reaches 8 * 7 * 7 mm, the equipment size is reduced, and the space utilization rate is improved; an airtight packaging structure is adopted, the reliability of the device is ensured, and the service life of the device is prolonged.

Description

Technical Field

[0001] The invention relates to the field of laser technology, in particular to a high-performance non-magnetic 795nm collimated laser light source applied to cold atom application fields such as rubidium atomic clocks and laser magnetometers. Background Art

[0002] In the fields of rubidium atomic clocks, laser magnetometers, etc., 795nm lasers are important light sources. Traditional 795nm lasers are usually packaged in conventional butterfly or coaxial packages. This packaging method introduces kovar materials, making the device highly magnetic. During the assembly of modules or equipment, in order to avoid the influence of magnetism on equipment performance, the laser needs to be magnetically shielded, which not only increases the assembly cost, but also brings performance risks.

[0003] Although COB packaging can avoid the introduction of magnetic materials, COB packaging is a non-airtight packaging and cannot provide a stable environment for the chip, which poses a great challenge to the reliability of the chip and makes it difficult for the device to reach its expected lifespan. In addition, conventional 795nm laser devices require collimation before the laser is injected into the gas chamber. The collimating lens is usually placed outside the laser. This design makes the optical path longer, which in turn leads to a larger size of the entire device. It cannot meet the needs in some application scenarios that have strict requirements on the size of the equipment.

[0004] Therefore, it is necessary to design a high-performance non-magnetic 795nm collimated laser light source to solve the above-mentioned problems. Summary of the invention

[0005] The purpose of the present invention is to provide a high-performance non-magnetic 795nm collimated laser light source to solve the magnetic problems, large size problems and low reliability problems of the existing 795nm laser. Specifically, it aims to achieve the following technical effects:

[0006] 1. Provide a non-magnetic packaging solution to make the device magnetic strength less than 1nT, meeting the application scenarios with strict requirements on magnetic field environment.

[0007] 2. Design ultra-small lasers, with the overall device size reaching 8X7X7mm, reducing the size of the equipment and improving space utilization.

[0008] 3. Adopt hermetic packaging structure to ensure the reliability of the device and extend the service life of the device.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A high-performance non-magnetic 795nm collimated laser light source, comprising a laser body, the laser body comprising:

[0011] 795nmVcse l laser chip, a GaAs-based vertical cavity surface emitting chip, is used to convert current into 795nm band laser, with an operating current of 1.5-3mA, an output power range of 1-2.5mW, and a magnetic intensity of <10pT;

[0012] Thermistor, composed of ceramic, resistance value is temperature sensitive, used to indicate temperature, magnetic strength <10pT;

[0013] Capacitor, made of ceramic, plays an ESD protection role, magnetic strength <10pT;

[0014] Ceramic substrate, made of aluminum nitride material, used to carry the 795nmVcse l laser chip, thermistor and capacitor, with a magnetic intensity of <10pT;

[0015] Thermoelectric cooler TEC, using the Peltier effect to control the laser temperature, magnetic intensity <50pT;

[0016] The primary refraction prism and the secondary refraction prism are both made of glass. The primary refraction prism is used to fold the light path by 90 degrees, and the secondary refraction prism is used to fold the light path twice so that the laser moves horizontally and then propagates in the reverse direction.

[0017] A Al alloy base, made of non-magnetic Al alloy, used to support the thermoelectric cooler TEC, the primary refraction prism and the secondary refraction prism;

[0018] A collimating lens and a lens base, wherein the collimating lens is made of glass material and is used to collimate the divergent laser, and the lens base is made of glass material and is used to carry the collimating lens;

[0019] The non-magnetic shell is made of oxygen-free copper, including an oxygen-free copper base plate, an oxygen-free copper ring frame, a light window bracket, a sapphire light window and a ceramic circuit board, which are used to provide an airtight chamber and circuit connection;

[0020] The cover plate is made of oxygen-free copper material and is welded to the non-magnetic tube shell to seal the tube shell chamber.

[0021] As a preferred solution of the present invention, the 795nmVcse l laser chip is welded to a ceramic substrate prefabricated with gold-tin solder through a eutectic welding process, the thermistor and capacitor are pasted to the ceramic substrate through silver glue, the ceramic substrate assembly is bonded to the thermoelectric cooler TEC through silver glue, the Al alloy base is mounted in the non-magnetic tube shell through welding or silver glue, the thermoelectric cooler TEC assembly is assembled on the boss of the Al alloy base through silver glue or solder welding, and the 795nmVcse l laser chip, capacitor, thermistor, and the upper electrode of the thermoelectric cooler TEC are connected to the ceramic circuit board through gold wire bonding.

[0022] As a preferred solution of the present invention, the secondary refractive prism is mounted on the column of the Al alloy base by an automatic mounting device and fixed with glue.

[0023] As a preferred solution of the present invention, the primary refractive prism is mounted on the bottom plane of the Al alloy base by an automatic mounting device and fixed with glue.

[0024] As a preferred solution of the present invention, the lens base is mounted to the bottom surface of the non-magnetic tube shell by automatic patch equipment and fixed with glue, and the collimating lens is fixed to the lens base with glue after spot coupling using a coupling table.

[0025] As a preferred solution of the present invention, the base material of the non-magnetic tube shell is non-magnetic oxygen-free copper, the surface is silver-copper plated, and it is brazed together with the ceramic circuit board, light window bracket, sealing ring and bottom plate by silver-copper solder. The cover plate is processed with oxygen-free copper and is air-tightly welded to the non-magnetic tube shell by laser welding technology.

[0026] As a preferred solution of the present invention, the magnetic intensity of the entire laser body device is <1nT, the size of the entire device is 8X7X7mm, the size of the collimated spot is 1.5-2mm, and the divergence angle is <0.1°.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the present invention, by setting up a high-performance non-magnetic 795nm collimated laser light source, the following effects can be achieved: 1. Low magnetism: by adopting non-magnetic tube shells and non-magnetic components, the magnetic intensity of the overall device is less than 1nT, which meets the cold atom application fields with extremely high requirements on magnetic field environment, such as rubidium atomic clocks, laser magnetometers, etc., avoids the interference of magnetism on equipment performance, and improves the accuracy and stability of the equipment; 2. Ultra-small size: through the collimated optical path design scheme, the special collimating lens and the chip are packaged in one, and the folded optical path is adopted, the overall device size reaches 8X7X7mm, which is smaller than the traditional 795nm laser. 1. The size of the optical device is greatly reduced, which is conducive to the miniaturized design of the equipment, improves the space utilization rate, and meets some application scenarios with strict requirements on the equipment size; 2. High reliability: The airtight packaging structure effectively protects the internal chips and other components, avoids the influence of external environmental factors such as moisture and dust on the device, ensures the reliability of the device, extends the service life of the device, and reduces the maintenance cost; 3. Excellent collimation characteristics: The collimated spot size is 1.5-2mm, and the divergence angle is less than 0.1°, which can provide high-quality collimated light source for cold atom applications and improve the performance of laser in related applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the internal main structure of the present invention;

[0031] Figure 3 It is a side view structural schematic diagram of the present invention;

[0032] Figure 4 It is a schematic diagram of the three-dimensional structure inside the present invention;

[0033] Figure 5 It is an exploded view of the present invention.

[0034] In the figure: 1. Laser body; 2. Primary refractive prism; 3. Secondary refractive prism; 4. Al alloy base; 5. Collimating lens; 6. Non-magnetic shell; 7. Cover plate. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given. 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 thorough and comprehensive.

[0037] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] For examples, see Figure 1-5, the present invention provides a technical solution:

[0040] A high-performance non-magnetic 795nm collimated laser light source, comprising a laser body 1, wherein the laser body 1 comprises:

[0041] 795nmVcse l laser chip is a GaAs-based vertical cavity surface emitting chip used to convert current into 795nm band laser. The working current is 1.5-3mA, the light output power range is 1-2.5mW, and the magnetic intensity is <10pT. It is the core component for generating lasers.

[0042] Thermistor, composed of ceramic, has temperature-sensitive resistance value and is used to indicate temperature, with magnetic intensity <10pT; the temperature is indicated by measuring the resistance value so as to monitor the temperature of the laser;

[0043] Capacitor, made of ceramic, plays the role of ESD static protection, magnetic strength <10pT, mainly plays the role of ESD static protection, to prevent static electricity from damaging the internal components of the laser;

[0044] Ceramic substrate, made of aluminum nitride material, used to carry the 795nmVcse l laser chip, thermistor and capacitor, with a magnetic strength of <10pT, providing a stable installation platform for other components;

[0045] Thermoelectric cooler TEC uses the Peltier effect to control the temperature of the laser. The magnetic intensity is <50pT, ensuring that the laser works at a suitable temperature.

[0046] The primary refraction prism and the secondary refraction prism are both made of glass. The primary refraction prism is used to fold the light path by degrees, and the secondary refraction prism is used to fold the light path twice so that the laser moves horizontally and then propagates in the reverse direction, further optimizing the light path, realizing the design of the folded light path, and reducing the overall size.

[0047] A l alloy base, made of non-magnetic Al alloy, is used to carry the thermoelectric cooler TEC, the primary refraction prism and the secondary refraction prism, providing a supporting structure for the internal components;

[0048] Collimating lens and lens base. The collimating lens is made of glass material and is used to collimate the divergent laser so that the laser is transmitted in the form of parallel light. The lens base is made of glass material and is used to carry the collimating lens.

[0049] The non-magnetic shell is made of oxygen-free copper, including an oxygen-free copper base plate, an oxygen-free copper ring frame, a light window bracket, a sapphire light window and a ceramic circuit board, which are used to provide an airtight chamber and circuit connection, ensure the stability of the internal environment of the laser, and realize electrical connection;

[0050] The cover plate is made of oxygen-free copper material and is welded to the non-magnetic tube shell to seal the tube shell chamber and ensure the airtight packaging effect.

[0051] Specifically, the 795nmVcse l laser chip is welded to a ceramic substrate prefabricated with gold-tin solder through a eutectic welding process, the thermistor and capacitor are adhered to the ceramic substrate through silver glue, the ceramic substrate assembly is bonded to the thermoelectric cooler TEC through silver glue, the Al alloy base 4 is mounted in the non-magnetic tube shell 6 through welding or silver glue, the thermoelectric cooler TEC assembly is assembled on the boss of the Al alloy base 4 through silver glue or soldering, and the 795nmVcse l laser chip, capacitor, thermistor, and the upper electrode of the thermoelectric cooler TEC are connected to the ceramic circuit board through gold wire bonding.

[0052] Specifically, the secondary refractive prism 3 is mounted on the column of the Al alloy base 4 by an automatic mounting device and fixed with glue.

[0053] Specifically, the primary refractive prism 2 is mounted on the bottom plane of the Al alloy base 4 by an automatic mounting device and fixed with glue.

[0054] Specifically, the lens base is mounted to the bottom surface of the non-magnetic tube shell 6 by an automatic patch device and fixed with glue, and the collimating lens 5 is fixed to the lens base with glue after spot coupling using a coupling table.

[0055] Specifically, the base material of the non-magnetic tube shell 6 is non-magnetic oxygen-free copper, the surface is silver-copper plated, and it is brazed together with the ceramic circuit board, the light window bracket, the sealing ring and the bottom plate by silver-copper solder. The cover plate 7 is made of oxygen-free copper and is airtightly welded to the non-magnetic tube shell 6 by laser welding technology.

[0056] Specifically, the overall device magnetic intensity of the laser body 1 is <1nT, the overall device size is 8X7X7mm, the collimated spot size is 1.5-2mm, and the divergence angle is <0.1°.

[0057] Workflow of the present invention:

[0058] 1. Preparation: First, select the 795nmVcse l laser chip, thermistor, capacitor, ceramic substrate, thermoelectric cooler TEC, primary refraction prism, secondary refraction prism, Al alloy base, collimating lens, lens base, non-magnetic shell, cover and other components that meet the requirements. Ensure that the oxygen-free copper material of the non-magnetic shell is non-magnetic and the silver and copper plating on the surface is uniform; check the quality of the aluminum nitride material of the ceramic substrate to ensure its flatness and load-bearing performance; test the performance parameters of other components to ensure that they meet the design requirements;

[0059] 2. Install the chip and components on the ceramic substrate: Heat the ceramic substrate with prefabricated gold-tin solder to the appropriate temperature, and use the eutectic welding process to weld the 795nm Vcse l laser chip to the ceramic substrate. Control the welding temperature and time to ensure that the welding is firm and does not damage the chip. Use silver glue to paste the ESD protection capacitor and thermistor to the specified position of the ceramic substrate, ensure that the pasting position is accurate, and the silver glue is evenly applied. After the silver glue is solidified, proceed to the next step;

[0060] 3. Assemble the ceramic substrate assembly with TEC and Al alloy base: Bond the ceramic substrate assembly coated with silver glue to the TEC, press gently to make the two fit tightly, and wait for the silver glue to solidify. Install the non-magnetic Al alloy base into the tube shell by welding or silver glue to ensure the accurate installation position. Then assemble the TEC assembly to the non-magnetic Al alloy base boss by silver glue or soldering to ensure stable connection and good electrical conduction;

[0061] 4. Installation of optical path components: Use automatic patch equipment to mount the secondary refraction prism to the column of the Al alloy base, and fix it with glue to ensure the accuracy of the prism position and the optical path refraction effect. Similarly, mount the primary refraction prism to the bottom plane of the Al alloy base through automatic patch equipment and fix it with glue. Mount the lens gasket to the bottom surface of the tube shell through automatic patch equipment and fix it with glue. Use a coupling table to couple the lens spot, constantly adjust the lens position, find the best position to minimize the divergence angle of the collimated light spot, and then fix the lens to the lens base with glue;

[0062] 5. Non-magnetic tube shell packaging: Install the ceramic circuit board, light window bracket and other components into the non-magnetic tube shell according to the design requirements, and use silver-copper solder to braze the oxygen-free copper base plate, oxygen-free copper ring frame, light window bracket and ceramic circuit board together to ensure welding quality and airtight performance. After all the components inside the tube shell are assembled, use the cover plate processed with oxygen-free copper and use the laser welding process to perform airtight welding with the tube shell to complete the packaging of the entire laser;

[0063] 6. Performance testing: Perform performance testing on the packaged 795nm collimated laser, use a high-precision magnetic field measuring instrument to detect the magnetic strength of the entire device to ensure that the magnetic strength is less than 1nT; use optical measuring equipment to measure the collimated spot size and divergence angle to ensure that the collimated spot size is 1.5-2mm and the divergence angle is less than 0.1°; perform aging tests on the laser to detect its reliability under different environmental conditions to ensure that it meets the design requirements.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-performance non-magnetic 795nm collimated laser light source, comprising a laser body (1), characterized in that: The laser body (1) comprises: 795nm Vcsel laser chip, a GaAs-based vertical cavity surface emitting chip, is used to convert current into 795nm band laser, with an operating current of 1.5-3mA, an output power range of 1-2.5mW, and a magnetic intensity of <10pT; Thermistor, composed of ceramic, resistance value is temperature sensitive, used to indicate temperature, magnetic strength <10pT; Capacitor, made of ceramic, plays an ESD protection role, magnetic strength <10pT; Ceramic substrate, made of aluminum nitride material, used to carry the 795nm Vcsel laser chip, thermistor and capacitor, with a magnetic intensity of <10pT; Thermoelectric cooler TEC, using the Peltier effect to control the laser temperature, magnetic intensity <50pT; The primary refraction prism (2) and the secondary refraction prism (3) are both made of glass. The primary refraction prism (2) is used to fold the light path by 90 degrees, and the secondary refraction prism (3) is used to fold the light path twice so that the laser light moves horizontally and then propagates in the reverse direction. An Al alloy base (4) made of a non-magnetic Al alloy and used for supporting the thermoelectric cooler TEC, the primary refraction prism and the secondary refraction prism; A collimating lens (5) and a lens base, wherein the collimating lens is made of glass material and is used to collimate divergent laser light, and the lens base is made of glass material and is used to carry the collimating lens; The non-magnetic tube shell (6) is made of oxygen-free copper, including an oxygen-free copper bottom plate, an oxygen-free copper ring frame, a light window bracket, a sapphire light window and a ceramic circuit board, and is used to provide an airtight chamber and circuit connection; The cover plate (7) is made of oxygen-free copper material and is welded to the non-magnetic tube shell to seal the tube shell chamber.

2. A high performance non-magnetic 795nm collimated laser light source according to claim 1, characterized in that: The 795nm Vcsel laser chip is welded to a ceramic substrate prefabricated with gold-tin solder through a eutectic welding process; the thermistor and capacitor are attached to the ceramic substrate through silver glue; the ceramic substrate assembly is bonded to the thermoelectric cooler TEC through silver glue; the Al alloy base (4) is mounted in the non-magnetic tube shell (6) through welding or silver glue; the thermoelectric cooler TEC assembly is assembled on the boss of the Al alloy base (4) through silver glue or soldering; the 795nm Vcsel laser chip, capacitor, thermistor, and the upper electrode of the thermoelectric cooler TEC are connected to the ceramic circuit board through gold wire bonding.

3. A high performance non-magnetic 795nm collimated laser light source according to claim 1, characterized in that: The secondary refractive prism (3) is mounted on the column of the Al alloy base (4) by an automatic mounting device and fixed by glue.

4. A high performance non-magnetic 795nm collimated laser light source according to claim 1, characterized in that: The primary refractive prism (2) is mounted on the bottom plane of the Al alloy base (4) by an automatic mounting device and fixed by glue.

5. A high performance non-magnetic 795nm collimated laser light source according to claim 1, characterized in that: The lens base is mounted on the bottom surface of the non-magnetic tube shell (6) by automatic patch equipment and fixed by glue, and the collimating lens (5) is fixed to the lens base by glue after spot coupling using a coupling platform.

6. A high performance non-magnetic 795nm collimated laser light source according to claim 1, characterized in that: The base material of the non-magnetic tube shell (6) is non-magnetic oxygen-free copper, the surface of which is silver-copper plated, and is brazed together with the ceramic circuit board, the light window bracket, the sealing ring and the bottom plate by silver-copper solder. The cover plate (7) is processed with oxygen-free copper and is airtightly welded to the non-magnetic tube shell (6) by laser welding technology.

7. A high performance non-magnetic 795nm collimated laser light source according to claim 1, characterized in that: The laser body (1) has an overall device magnetic intensity of <1 nT, an overall device size of 8 x 7 x 7 mm, a collimated light spot size of 1.5-2 mm, and a divergence angle of <0.1°.

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