Beam combining semiconductor laser and packaging method

Abstract

The invention relates to a beam-combining semiconductor laser and a packaging method, and belongs to the technical field of semiconductor laser packaging. The beam-combining semiconductor laser comprises a shell and a semiconductor laser chip; semiconductor laser chips are divided into two rows with a height difference, after fast axis collimation is carried out on the chips, the chips in the first row adopt a meniscus slow axis collimating mirror, the chips in the second row adopt a plano-convex slow axis collimating mirror to carry out collimation on the slow axes of the chips, and the plano-convex slow axis collimating mirror is located over the meniscus slow axis collimating mirror; after the two rows of slow axes are collimated, light beams are reflected by a front small reflector and a rear small reflector respectively for space beam combination, the height of the light beams of the second row of chips is reduced to the position with the same height as that of the light beams of the first row of chips through the refraction effect of a prism, then the two rows of light beams are overlapped through wavelength beam combination or polarization beam combination, and the combined light beams are coupled into an optical fiber through a focus lens. According to the invention, the working distance between the chips and between the slow axis collimating lens and the chips is reduced, so that the size and weight of the module are reduced.

Description

Technical Field

[0001] The present invention relates to a combined semiconductor laser and a packaging method thereof, belonging to the technical field of semiconductor laser packaging. Background Art

[0002] Semiconductor lasers are widely used in pumping of solid-state lasers and fiber lasers, as well as directly in laser processing, medical beauty, material processing, night vision lighting and other fields due to their characteristics such as small volume, light weight, long life, and high efficiency. However, the output power of a single semiconductor laser chip is relatively low. To obtain high-power laser output, technologies such as spatial beam combining, polarization beam combining, and wavelength beam combining are usually used to couple the light output of multiple chips into a single fiber for output.

[0003] To ensure the service life of the module, heat dissipation of the chip is required, and usually a metal material with high thermal conductivity is used as the packaging heat dissipation housing. For example Figure 1 For a module using spatial beam combining technology and polarization beam combining technology for fiber coupling output, semiconductor laser chips are divided into two rows and packaged on a metal base plate. The light output directions of the two rows of chips are the same. To avoid light blocking, the positions of the front and rear rows of chips are staggered with each other. The light beams emitted by each row of semiconductor lasers are collimated along the fast axis and the slow axis, and then reflected by a small mirror to form spatial beam combining. The two rows of light beams form polarization beam combining through the action of a large mirror and a polarization beam splitter prism with a wave plate and are coupled into the fiber. In this arrangement, the distance between adjacent chips is relatively large. Limited by the working distance of the slow axis collimator, the distance between the slow axis collimator and the laser chip is relatively large. In recent years, the market demand for the power of the module has been increasing day by day, the number of integrated chips in a single module is increasing, and the volume and weight of the module are also increasing accordingly, which limits its application in high-end fields such as aerospace. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, to solve the problems of large volume and high weight of the semiconductor laser module, a combined semiconductor laser and its packaging method are provided. Through this method, the volume and weight of the module can be effectively reduced.

[0005] The technical solution of the present invention is as follows:

[0006] A combined semiconductor laser, the beam combining device adopts spatial beam combining and polarization beam combining technologies, and includes a housing and semiconductor laser chips;

[0007] The semiconductor laser chips are divided into two rows, and chips with different wavelengths are divided into two rows and packaged on the bottom plate of the housing. The light output directions of the chips are the same. The second row of chip groups is located directly behind the first row of chip groups and is higher in position than the first row of chip groups;

[0008] A fast-axis collimating mirror is arranged in the light-emitting direction of each chip. Then, a meniscus-shaped slow-axis collimating mirror and a front small mirror are arranged in the light-emitting direction of the chips in the first row, and a plano-convex slow-axis collimating mirror and a rear small mirror are arranged in the light-emitting direction of the chips in the second row. The slow-axis collimating lens is used to collimate the slow axis of the chip, and the plano-convex slow-axis collimating lens is located directly above the meniscus-shaped slow-axis collimating lens; the front small mirror and the rear small mirror are placed front and back, and the rear small mirror is higher than the front small mirror; the transmission directions of the light beams of the two groups of chips are changed to achieve spatial beam combining;

[0009] A prism is arranged in the light-emitting direction of the front small mirror and the rear small mirror. The prism is used to reduce the beam height of the chips in the second row to the same height as the beam of the chips in the first row through the refraction of the prism;

[0010] A beam combining structure is arranged in the light-emitting direction of the prism for combining the light beams of the two rows of chips; a focusing mirror and an optical fiber are sequentially arranged in the light-emitting direction of the beam combining structure. The focusing mirror is used to couple the combined light beam into the optical fiber.

[0011] Preferably, the chip group in the second row is 0.5 - 2 mm higher than the chip group in the first row. Correspondingly, the plano-convex slow-axis collimating lens is 0.5 - 2 mm higher than the meniscus-shaped slow-axis collimating lens, and the rear small mirror is 0.5 - 2 mm higher than the front small mirror.

[0012] Preferably, the horizontal distance between the chip group in the second row and the chip group in the first row is 5 - 10 mm.

[0013] Preferably, the beam combining structure is a polarization beam splitter prism or a wavelength beam combining mirror for polarization beam combining or wavelength beam combining; a wave plate is arranged on one side of the polarization beam splitter prism facing the prism; a large mirror is arranged beside the wavelength beam combining mirror, and the large mirror is used to reflect the light beam of one row of chips.

[0014] In the semiconductor laser of the present invention, by first placing the two rows of chips facing each other and then raising the height of the second row of chips, the distance between the chips is effectively reduced. By using the meniscus slow-axis collimating lens, the working distance between the slow-axis collimating lens and the chip is reduced, thereby reducing the space occupied in the slow-axis direction. Through the action of the prism, the beam heights of the two rows of chips are kept consistent, and at the same time, the secondary reflection of the polarization beam splitter prism makes the optical paths of the front and rear two rows of chips equal.

[0015] A packaging method for a beam-combined semiconductor laser includes the following steps:

[0016] (1) Sinter two groups of chips onto the bottom plate of the housing. The wavelengths of the two groups of chips are the same or different. The chips in the second row are located 5 - 10 mm behind the chips in the first row and are 0.5 - 2 mm higher than the chips in the first row in the vertical direction;

[0017] (2) A fast-axis collimating mirror is arranged in the light-emitting direction of each chip to collimate the fast axis of each chip;

[0018] (3) A meniscus-shaped slow-axis collimating mirror and a plano-convex slow-axis collimating mirror are arranged on the bottom plate of the housing. The plano-convex slow-axis collimating lens is located directly above the meniscus-shaped slow-axis collimating lens. The first row and the second row of chips are respectively collimated by the meniscus-shaped slow-axis collimating mirror and the plano-convex slow-axis collimating mirror.

[0019] (4) A front small mirror and a rear small mirror are arranged on the bottom plate of the housing. The front small mirror and the rear small mirror are placed front and back. The front small mirror is close to the meniscus-shaped slow-axis collimating mirror and is 0.5 - 2 mm shorter than the rear small mirror. The light beams of the first row and the second row of chips are respectively changed in direction by the front small mirror and the rear small mirror to form spatial beam combination.

[0020] (5) A prism is arranged in the light output direction of the front small mirror and the rear small mirror. The light beam of the second row of chips passes through the prism, and the center height of the light beam is reduced by 0.5 - 2 mm to be equal in height to the light beam of the first row of chips.

[0021] (6) A beam combination structure is arranged in the light output direction of the prism. When the wavelengths of the two rows of chips are the same, polarization beam combination is adopted. A polarization beam splitter prism is placed. A wave plate is arranged on one side of the polarization beam splitter prism facing the prism. The light beam of the second row of chips passes through the polarization beam splitter mirror. The light beam of the first row of chips passes through the wave plate of the polarization beam splitter mirror and is reflected to overlap with the light beam of the first row of chips to achieve polarization beam combination.

[0022] (7) When the wavelengths of the two rows of chips are different, wavelength beam combination is adopted. A wavelength beam combination mirror is placed. A large mirror is arranged beside the wavelength beam combination mirror. The light beam of the second row of chips passes through the wavelength beam combination mirror. The light beam of the first row of chips is reflected by the large mirror and overlaps with the light beam of the first row of chips to achieve wavelength beam combination.

[0023] (8) A focusing lens and an optical fiber are sequentially arranged in the light output direction of the beam combination structure. The combined light beam is coupled into the optical fiber by using the focusing lens.

[0024] The beneficial effects of the present invention are as follows:

[0025] The present invention reduces the working distances between chips and between the slow-axis collimating lens and the chips. Through packaging the chips in two groups with a height difference and the use of the meniscus slow-axis collimating lens and the prism, module packaging with small volume and low weight is achieved. Brief Description of the Drawings

[0026] Figure 1 Top view schematic diagram of the polarization beam combination semiconductor laser of the present invention;

[0027] Figure 2 Stereo schematic diagram of the polarization beam combination semiconductor laser of the present invention;

[0028] Figure 3 Top view schematic diagram of the wavelength beam combination semiconductor laser of the present invention;

[0029] Figure 4 Schematic three-dimensional diagram of the wavelength combined semiconductor laser of the present invention;

[0030] Figure 5 Schematic diagram of reducing the beam center height by the prism of the present invention;

[0031] The numerical marks in the figure respectively represent: 1 - semiconductor laser chip, 2 - fast axis collimating mirror, 3 - meniscus slow axis collimating mirror, 4 - plano-convex slow axis collimating mirror, 5 - front small reflector, 6 - rear small reflector, 7 - wave plate, 8 - polarization beam splitter prism, 9 - large reflector, 10 - wavelength combining mirror, 11 - focusing mirror, 12 - optical fiber, 13 - housing, 14 - prism. Detailed implementation manners

[0032] The present invention will be further described below by way of examples in conjunction with the accompanying drawings, but not limited thereto.

[0033] Example 1:

[0034] A combined semiconductor laser, the combining device adopts spatial beam combining and polarization beam combining technologies, and includes a housing 13 and a semiconductor laser chip 1.

[0035] As Figure 1-2 shown, the semiconductor laser chips are divided into two rows, the horizontal distance between the second row of chip groups and the first row of chip groups is 5 mm, chips of different wavelengths are packaged on the bottom plate of the housing in two rows according to wavelengths, the light emitting directions of the chips are the same, the second row of chip groups is located directly behind the first row of chip groups, and is 0.5 mm higher than the first row of chip groups.

[0036] A fast axis collimating mirror 2 is arranged in the light emitting direction of each chip. Then, a meniscus slow axis collimating mirror 3 and a front small reflector 5 are arranged in the light emitting direction of the first row of chips, and a plano-convex slow axis collimating mirror 4 and a rear small reflector 6 are arranged in the light emitting direction of the second row of chips. The slow axis collimating lens is used to collimate the slow axis of the chip. The plano-convex slow axis collimating lens is located directly above the meniscus slow axis collimating lens; the front small reflector and the rear small reflector are placed front and back, and the rear small reflector is 0.5 mm higher than the front small reflector; the beam transmission directions of the two groups of chips are changed to achieve spatial beam combining.

[0037] A prism 14 is arranged in the light emitting direction of the front small reflector and the rear small reflector. The prism is used to reduce the beam height of the second row of chips to the same height as the beam of the first row of chips through the refraction effect of the prism.

[0038] A combining structure is arranged in the light emitting direction of the prism for combining the beams of the two rows of chips; the combining structure is a polarization beam splitter prism 8, and a wave plate 7 is arranged on the side of the polarization beam splitter prism facing the prism.

[0039] A focusing lens 11 and an optical fiber 12 are sequentially arranged in the light output direction of the beam combining structure. The focusing lens is used to couple the combined beam into the optical fiber.

[0040] Embodiment 2:

[0041] A beam combining semiconductor laser has the same structure as that in Embodiment 1, except that the wavelengths of the two rows of chips are different and wavelength beam combining is required. As Figure 3-4 shown, the beam combining structure is a wavelength beam combining mirror 10, and a large reflecting mirror 9 is arranged beside the wavelength beam combining mirror. The large reflecting mirror is used to reflect the beam of one row of chips.

[0042] Embodiment 3:

[0043] A beam combining semiconductor laser has the same structure as that in Embodiment 1, except that the second row of chip groups is 2 mm higher than the first row of chip groups. Correspondingly, the plano-convex slow-axis collimating lens is 2 mm higher than the meniscus-shaped slow-axis collimating lens, and the rear small reflecting mirror is 2 mm higher than the front small reflecting mirror. The horizontal distance between the second row of chip groups and the first row of chip groups is 10 mm.

[0044] Embodiment 4:

[0045] A packaging method for the beam combining semiconductor laser described in Embodiment 1 or 2 includes the following steps:

[0046] (1) Sinter the chips in two groups onto the bottom plate of the housing. The wavelengths of the two groups of chips are the same or different. The second row of chips is located 5 mm behind the first row of chips and is 0.5 mm higher than the first row of chips in the vertical direction;

[0047] (2) A fast-axis collimating mirror is arranged in the light output direction of each chip to perform fast-axis collimation on each chip;

[0048] (3) A meniscus-shaped slow-axis collimating mirror and a plano-convex slow-axis collimating mirror are arranged on the bottom plate of the housing. The plano-convex slow-axis collimating lens is directly above the meniscus-shaped slow-axis collimating lens. The first row and the second row of chips are respectively collimated by the meniscus-shaped slow-axis collimating mirror and the plano-convex slow-axis collimating mirror;

[0049] (4) A front small reflecting mirror and a rear small reflecting mirror are arranged on the bottom plate of the housing. The front small reflecting mirror and the rear small reflecting mirror are placed front and back. The front small reflecting mirror is close to the meniscus-shaped slow-axis collimating mirror and is 0.5 mm shorter than the rear small reflecting mirror. The beams of the first row and the second row of chips are respectively changed in the beam direction by the front small reflecting mirror and the rear small reflecting mirror to form spatial beam combining;

[0050] (5) A prism is arranged in the light output direction of the front small reflecting mirror and the rear small reflecting mirror. The beam of the second row of chips passes through the prism, and the beam center height is reduced by 0.5 mm to be equal in height to the beam of the first row of chips;

[0051] (6) A beam combining structure is arranged in the light output direction of the prism. When the wavelengths of the two rows of chips are the same, polarization beam combining is adopted. A polarization beam splitter prism is placed, and a wave plate is provided on the side of the polarization beam splitter prism facing the prism. The light beam of the second row of chips passes through the polarization beam splitter, and the light beam of the first row of chips passes through the wave plate of the polarization beam splitter and then overlaps with the light beam of the first row of chips after reflection, realizing polarization beam combining;

[0052] (7) When the wavelengths of the two rows of chips are different, wavelength beam combining is adopted. A wavelength beam combining mirror is placed, and a large reflector is arranged beside the wavelength beam combining mirror. The light beam of the second row of chips passes through the wavelength beam combining mirror, and the light beam of the first row of chips overlaps with the light beam of the first row of chips after being reflected by the large reflector, realizing wavelength beam combining;

[0053] (8) A focusing lens and an optical fiber are sequentially arranged in the light output direction of the beam combining structure. The combined light beam is coupled into the optical fiber by using the focusing lens.

Claims

1. A combined semiconductor laser, comprising a housing and a semiconductor laser chip, characterized in that ； The semiconductor laser chips are divided into two rows, and the chips are encapsulated on the bottom plate of the housing in two rows. The light-emitting directions of the chips are the same. The second row of chip groups is located directly behind the first row of chip groups and is higher than the first row of chip groups in position. A fast-axis collimating mirror is arranged in the light-emitting direction of each chip. Then, a crescent-shaped slow-axis collimating mirror and a front small mirror are arranged in the light-emitting direction of the first row of chips, and a plano-convex slow-axis collimating mirror and a rear small mirror are arranged in the light-emitting direction of the second row of chips. The plano-convex slow-axis collimating lens is located directly above the crescent-shaped slow-axis collimating lens; the front small mirror and the rear small mirror are placed front and back, and the rear small mirror is higher than the front small mirror. A prism is arranged in the light-emitting directions of the front small mirror and the rear small mirror. The prism is used to reduce the beam height of the second row of chips to the same height as the beam of the first row of chips. A beam combining structure is arranged in the light-emitting direction of the prism, which is used to combine the beams of the two rows of chips; a focusing mirror and an optical fiber are sequentially arranged in the light-emitting direction of the beam combining structure. The focusing mirror is used to couple the combined beam into the optical fiber.

2. The combined semiconductor laser according to claim 1, characterized in that The second row of chip groups is 0.5 - 2 mm higher than the first row of chip groups in position. Correspondingly, the plano-convex slow-axis collimating lens is 0.5 - 2 mm higher than the crescent-shaped slow-axis collimating lens, and the rear small mirror is 0.5 - 2 mm higher than the front small mirror.

3. The combined semiconductor laser according to claim 1, characterized in that, The horizontal distance between the second row of chip groups and the first row of chip groups is 5 - 10 mm.

4. The combined semiconductor laser according to claim 1, characterized in that, The beam combining structure is a polarization beam splitting prism or a wavelength beam combining mirror for polarization beam combining or wavelength beam combining; a wave plate is arranged on one side of the polarization beam splitting prism facing the prism; a large mirror is arranged beside the wavelength beam combining mirror, and the large mirror is used to reflect the beam of one row of chips.

5. A packaging method for a combined semiconductor laser, characterized in that, It includes the following steps: (1) Sinter the chips in two groups onto the bottom plate of the housing. The wavelengths of the two groups of chips are the same or different. The second row of chips is located 5 - 10 mm behind the first row of chips and is 0.5 - 2 mm higher than the first row of chips in the vertical direction. (2) A fast-axis collimating mirror is arranged in the light-emitting direction of each chip to collimate the fast axis of each chip. (3) A crescent-shaped slow-axis collimating mirror and a plano-convex slow-axis collimating mirror are arranged on the bottom plate of the housing. The plano-convex slow-axis collimating lens is located directly above the crescent-shaped slow-axis collimating lens. The first row and the second row of chips are respectively collimated by the crescent-shaped slow-axis collimating mirror and the plano-convex slow-axis collimating mirror. (4) A front small mirror and a rear small mirror are arranged on the bottom plate of the housing. The front small mirror and the rear small mirror are placed front and back. The front small mirror is close to the crescent-shaped slow-axis collimating mirror and is 0.5 - 2 mm shorter than the rear small mirror. The beams of the first row and the second row of chips respectively change the beam directions by the front small mirror and the rear small mirror to form spatial beam combination. (5) A prism is arranged in the light-emitting directions of the front small mirror and the rear small mirror. The beam of the second row of chips passes through the prism, and the beam center height is reduced by 0.5 - 2 mm to be the same as the beam of the first row of chips. (6) A beam combining structure is arranged in the light-emitting direction of the prism. When the wavelengths of the two rows of chips are the same, polarization beam combining is adopted. Place a polarization beam splitting prism. A wave plate is arranged on one side of the polarization beam splitting prism facing the prism. The beam of the second row of chips passes through the polarization beam splitter. The beam of the first row of chips passes through the wave plate of the polarization beam splitter and then is reflected to overlap with the beam of the first row of chips to achieve polarization beam combining. (7) When the wavelengths of the two rows of chips are different, wavelength beam combination is adopted. A wavelength beam combiner is placed, and a large reflector is set beside the wavelength beam combiner. The light beam of the second row of chips passes through the wavelength beam combiner, and the light beam of the first row of chips overlaps with the light beam of the first row of chips after being reflected by the large reflector, realizing wavelength beam combination; (8) A focusing lens and an optical fiber are sequentially arranged in the light output direction of the beam combination structure, and the combined light beam is coupled into the optical fiber by using the focusing lens.

Images