JP2013016585A - Multi-wavelength semiconductor laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that the chip size increases when configuring a three-wavelength semiconductor laser device by arranging a two-wavelength laser consisting of a red laser diode and an infrared laser diode, and a blue-violet laser diode side by side, because the distance between the light-emitting points of two lasers in the two-wavelength laser is limited, and that the manufacturing cost increases when stacking the two-wavelength laser and the blue-violet laser vertically because the assembly process is complicated.SOLUTION: A three-wavelength semiconductor laser device is configured by mounting a blue-violet laser diode and a two-wavelength laser diode, having the light-emitting points formed near the chip end, side by side. This can provide an easy-to-manufacture three-wavelength semiconductor laser device in which three light-emitting points can be brought close to each other.

Description

  The present invention relates to a multiwavelength semiconductor laser device having a plurality of laser diodes that emit light having different wavelengths.

  Optical disks such as CDs, DVDs, and BDs (Blu-ray Discs) are currently actively used as large-capacity recording media. Laser diodes (hereinafter referred to as LDs) used for recording / reproduction of these optical discs have different oscillation wavelengths, the CD LD oscillation wavelength is 780 nm band (infrared), and the DVD LD oscillation wavelength is 650 nm band (red). ), The oscillation wavelength of the LD for BD is a 405 nm band (blue-violet). Therefore, in order to handle CD, DVD, and BD information with one optical disk device, three light sources of infrared, red, and blue-violet are required.

  When a multi-wavelength semiconductor laser device is configured by horizontally arranging LD chips having different wavelengths, particularly when a three-wavelength semiconductor laser device is configured by horizontally arranging a two-wavelength LD composed of a red LD and an infrared LD and a blue-violet LD. Since the distance between the light emitting points of the two lasers of the LD is limited on the equipment, the chip size is increased. Therefore, as a conventional multi-wavelength semiconductor laser device, information on CD, DVD, and BD can be obtained with one optical disk device by adhering a red LD and an infrared LD in parallel on a blue-violet LD installed on a heat sink. There is one that can be handled (for example, see Patent Document 1).

JP 2006-59471 A

  However, in the multi-wavelength laser device described in Patent Document 1, since the infrared LD and the red LD are disposed on the blue-violet LD, the heat generated by the infrared LD and the red LD during operation is used as a heat sink. There was a problem that heat could not be efficiently dissipated. In addition, there is a problem that the assembly process becomes complicated and the manufacturing cost increases.

  The present invention has been made to solve the above problems, and provides a multi-wavelength semiconductor laser device having a small chip size, easy optical design, and easy manufacture.

  A multi-wavelength semiconductor laser device according to the present invention includes a first laser unit that emits light of a first oscillation wavelength and a second laser unit that emits light of a second oscillation wavelength on a first substrate. A first laser diode having a semiconductor multilayer structure formed on a second substrate, and a third laser unit that emits light of a third oscillation wavelength, wherein the resonator of the third laser unit includes: A second laser diode formed at a position shifted from the center line in the stacking direction of the semiconductor stacked structure and the direction perpendicular to the resonator direction toward the one end, the first laser diode and the second laser diode; A submount for mounting is provided, and the second laser diode is mounted on the submount so as to be adjacent to the first laser diode on the one end side.

  The multi-wavelength semiconductor laser device according to the present invention includes a first laser unit that emits light having a first oscillation wavelength and a second laser that emits light having a second oscillation wavelength on a first substrate. A first laser diode having a laser section; a second laser diode having a semiconductor multilayer structure on a second substrate; and emitting light having a third oscillation wavelength; the first laser diode; The first laser diode and the second laser diode are mounted on the submount so as to be adjacent to each other, and the first laser diode is disposed on the resonator side. Is mounted on the submount side, and the second laser diode is mounted with the second substrate side on the submount side. Other features of the present invention will become apparent below.

  According to the present invention, a multi-wavelength semiconductor laser device having a small chip size, easy optical design, and easy manufacture can be obtained.

1 is a schematic perspective view showing the structure of a multiwavelength semiconductor laser device according to an embodiment of the present invention. It is a schematic sectional drawing which shows the structure of the multiwavelength semiconductor laser apparatus which concerns on one embodiment of this invention. 1 is a schematic side view showing the structure of a multiwavelength semiconductor laser device according to an embodiment of the present invention. It is a schematic perspective view which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic side view which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic sectional drawing which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic sectional drawing which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic sectional drawing which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic side view which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic sectional drawing which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic side view which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention. It is a schematic sectional drawing which shows the structure of the multiwavelength semiconductor laser apparatus based on another embodiment of this invention.

Embodiment 1 FIG.
FIG. 1 is a perspective view of the multiwavelength semiconductor laser device according to the first embodiment. FIG. 2 is a cross-sectional view showing a laminated structure of a two-wavelength LD and a blue-violet LD mounted on the multi-wavelength semiconductor laser device of the first embodiment. FIG. 3 is a side view of the multi-wavelength semiconductor laser device according to the first embodiment viewed from one direction orthogonal to the laser beam emission direction. The multiwavelength semiconductor laser device according to the embodiment includes a stem 101 obtained by forming a metal plate into a disk shape, a block 103 placed on the upper surface of the stem 101, and a sub placed on one plane constituting the block 103. And a mount 105. On the submount 105, a two-wavelength LD 107 and a blue-violet LD 109 are mounted. The two-wavelength LD 107 has a semiconductor laminated structure on the first substrate 207, and an infrared laser unit 201 that emits infrared laser light having a wavelength of 780 nm as a first laser unit, and a wavelength of 650 nm as a second laser unit. The red laser part 203 that emits the red laser light is monolithically formed. A first back surface n-side electrode 209 is formed on the back surface. The blue-violet LD 109 has a third laser unit 205 in which a nitride semiconductor is stacked on a second substrate 211, and emits a blue-violet laser beam having a wavelength of 405 nm. A second back surface n-side electrode 213 is formed on the back surface. The resonator 117 of the blue-violet LD 109 is formed at a position displaced from the center line 215 of the chip toward the one end 217 of the chip in the direction perpendicular to the resonator direction and the semiconductor lamination direction. The lead pin 111 provided through the stem 101 is electrically connected to the two-wavelength LD 107 and the blue-violet LD 109 via the bonding wire 113, and the ground pin 115 penetrates the stem 101 and is electrically connected to the stem 101. ing.

  The block 103 is made of a metal material having a high thermal conductivity such as a copper alloy, and efficiently dissipates heat generated by the two-wavelength LD 107 and the blue-violet LD 109.

  A two-wavelength LD 107 and a blue-violet LD 109 are adjacently soldered onto a submount 105 placed on the block 103. The blue-violet LD 109 is mounted on the submount 105 so that the one end 217 side where the resonator is formed deviating from the center line 215 is adjacent to the two-wavelength LD 107. The laser beams emitted from the two-wavelength LD 107 and the blue-violet LD 109 are arranged so as to be emitted in the same direction. The order in which the block 103, the submount 105, and the two LDs are installed is not particularly limited.

  The lead pin 111 penetrates the stem 101 through an insulator, and is electrically connected to the p-side electrode 301 of the two-wavelength LD 107 and the p-side electrode 303 of the blue-violet LD 109 by a bonding wire 113.

  The ground pin 115 is joined to the stem 101 by welding, and the block 103 and the submount 105 are electrically connected to the ground pin 115 via the stem 101. A GND wiring pattern 305 is formed on the submount 105, and the two-wavelength LD 107 and the blue-violet LD 109 are connected to the GND wiring pattern 305, the first back surface n-side electrode 209, and the second n-side electrode 213. Are disposed on the submount 105 and electrically connected to the ground pin 115. Further, the GND wiring pattern 305 and the ground pin 115 on the submount 105 are electrically connected by a bonding wire 113.

  By configuring the multi-wavelength semiconductor laser device in this way, it is possible to obtain a multi-wavelength semiconductor laser device having a small chip size while satisfying the restriction on the distance between the light emitting points of the two lasers of the two-wavelength LD 107.

  Further, in the first embodiment, the resonators of the two lasers of the two-wavelength LD 107 and the resonator 117 of the blue-violet LD 109 are in the same direction, and the two lasers of the two-wavelength LD 107 emit light as shown in FIG. The points 219 and 221 and the light emission point 223 of the blue-violet LD 109 are aligned on the same plane in the resonator direction. Therefore, optical design such as the arrangement of the monitor PD can be facilitated. Further, by adjusting the distance between the two-wavelength LD 107 and the blue-violet LD 109, the distances between the light emitting points can be made equal.

  According to the first embodiment, the multi-wavelength semiconductor laser device is mounted so that the two-wavelength LD having a restriction on the distance between the light emission points of the two lasers and the blue-violet LD whose light emission points are shifted from the center are adjacent to each other. Thus, the distance between the light emitting points can be made equal. Alternatively, it is possible to obtain a multi-wavelength semiconductor laser device that can be designed so that the optical system becomes small in a state where the restriction on the distance between the emission points of the two lasers of the two-wavelength LD 107 is satisfied. In addition, the two laser resonators of the two-wavelength LD 107 and the blue-violet LD 109 have the same direction, and the two light-emitting points 219 and 221 of the two-wavelength LD 107 and the light-emitting point 223 of the blue-violet LD 109 are the same in the resonator direction. Since they are aligned on a plane, optical design can be facilitated.

  In the first embodiment, the GND wiring pattern 305 and the ground pin 115 of the submount 105 are electrically connected by the bonding wire 113, but the ground pin 115 and the stem 101 are joined by welding. Since the stem 101, the block 103, and the submount 105 are electrically connected, the bonding wire 113 between the GND wiring pattern 301 and the ground pin 115 on the submount 105 can be omitted.

Embodiment 2. FIG.
FIG. 4 is a perspective view of a multi-wavelength semiconductor laser device according to another embodiment 2 of the present invention. FIG. 5 is a side view of the multi-wavelength semiconductor laser device according to the second embodiment with respect to the laser beam emission direction.

  In the multi-wavelength semiconductor laser device according to the second embodiment, when the two-wavelength LD 107 is stacked on the submount 105, the two light emitting points 219 and 221 are on the submount 105 side, and the first n of the substrate 207 is first n. The side electrodes 209 are stacked in a junction down direction away from the submount 105. The two-wavelength LD 107 generates a large amount of heat and is mounted in a junction-down manner so that heat generated from the resonator can be efficiently radiated through the submount 105. The blue-violet LD 109, which has less heat dissipation problems than the two-wavelength LD 107, is mounted with a junction-up that is easy to assemble. When the horizontal position of the optical axis of the blue-violet LD 109 is separated from each optical axis of the two-wavelength LD 107 and the optical design of the two-wavelength LD 107 and the blue-violet LD 109 is performed separately, the resonator of the blue-violet LD 109 is formed at a position shifted from the center of the chip. do not have to. On the submount 105, a signal pattern 501 for the two-wavelength LD 107 and a GND pattern 503 for the blue-violet LD 109 are formed. The submount 105 and the signal pattern 501 on the submount 105 are electrically insulated by an insulating film or the like. Other configurations of the second embodiment are the same as those of the first embodiment. When there are restrictions on the distance between the emission points of the two lasers of the two-wavelength LD 107 and the optical system of the blue-violet LD 109, the resonator of the blue-violet LD 109 is formed at a position shifted from the center of the chip as in the first embodiment. Thus, it is possible to reduce the size of the external optical system and to obtain a multiwavelength semiconductor laser device excellent in heat dissipation.

  According to the second embodiment, since the multi-wavelength semiconductor laser device is mounted with the two-wavelength LD 107 junction-down and the blue-violet LD 109 junction-up, it is possible to obtain a multi-wavelength semiconductor laser device that is excellent in heat dissipation and easy to assemble. it can.

Embodiment 3 FIG.
FIG. 6 is a cross-sectional view showing a laminated structure of a two-wavelength LD and a blue-violet LD mounted on a multi-wavelength semiconductor laser device according to another embodiment 3 of the present invention. In the multi-wavelength semiconductor laser device according to the third embodiment, a step 601 is formed on the submount 105 on which the two-wavelength LD 107 and the blue-violet LD 109 are mounted, and the mounting positions of the two-wavelength LD 107 and the blue-violet LD 109 are perpendicular to the resonator direction. It is in a different position on the cross section. Other configurations of the third embodiment are the same as those of the second embodiment. In addition, the emission points 219 and 221 of the two lasers of the two-wavelength LD 107 and the emission point 223 of the blue-violet LD 109 are aligned on the same plane in the resonator direction. Other configurations of the third embodiment are the same as those of the second embodiment.

  By constructing the multi-wavelength semiconductor laser device in this way, it becomes possible to bring the two laser emission points 219 and 221 of the two-wavelength LD 107 closer to the emission point 223 of the blue-violet LD 109 on the vertical cross section with respect to the resonator direction. Thus, it is possible to reduce the size of the optical system and to obtain a multiwavelength semiconductor laser device excellent in heat dissipation. It is also possible to align the emission points 219 and 221 of the two lasers of the two-wavelength LD 107 and the emission point 223 of the blue-violet LD 109 on the same plane in the resonator direction, thereby facilitating optical design such as the arrangement of the monitor PD. Can do.

Embodiment 4 FIG.
FIG. 7 is a cross-sectional view showing a laminated structure of a two-wavelength LD and a blue-violet LD mounted on a multi-wavelength semiconductor laser device according to another embodiment 4 of the present invention. In the multiwavelength semiconductor laser device according to the fourth embodiment, a part of the two-wavelength LD 107 and the blue-violet LD 109 mounted on the submount 105 in which the step is formed has an overlapping portion 701 in the vertical direction. Other configurations of the fourth embodiment are the same as those of the second embodiment.

  By constructing the multi-wavelength semiconductor laser device in this way, it becomes possible to bring the two laser emission points 219 and 221 of the two-wavelength LD 107 closer to the emission point 223 of the blue-violet LD 109 on the vertical cross section with respect to the resonator direction. Thus, it is possible to reduce the size of the optical system and to obtain a multiwavelength semiconductor laser device excellent in heat dissipation.

Embodiment 5 FIG.
8 and 9 are schematic views showing the structure of a multiwavelength semiconductor laser device according to another embodiment 5 of the present invention. FIG. 8 is a schematic cross-sectional view of the multi-wavelength semiconductor laser device of the fifth embodiment, and FIG. 9 is a schematic side view. In the multi-wavelength semiconductor laser device according to the fifth embodiment, the first plane portion 801 and the first plane portion having the inner angle θ1 are formed on the submount 105 on which the two-wavelength LD 107 and the blue-violet LD 109 are mounted. The first side wall portion 805 having the side surface 803 is formed. The two-wavelength LD 107 is mounted on the first flat surface portion 801, and the blue-violet LD 109 is mounted on the first side wall portion 805 so that the second substrate side faces the first side surface 803. A signal wiring pattern 807 and a GND wiring pattern 809 are formed on the first plane portion 801 and the first side wall portion 805. In the fifth embodiment, since the two-wavelength LD 107 is mounted with junction-down and the blue-violet LD 109 is mounted with junction-up, a signal wiring pattern 807 is formed on the first plane portion 801, and the first sidewall portion 805 is formed. A GND wiring pattern 809 is formed in the. The signal wiring pattern 807 and the GND wiring pattern 809 are connected to the lead pin 111 or the ground pin 115 by the bonding wire 113. Other configurations of the fifth embodiment are the same as those of the first embodiment. Further, by forming a first recess 811 between the first flat surface portion 801 and the first side wall portion 805, the two laser emission points 219 and 221 of the two-wavelength LD 107 and the emission point 223 of the blue-violet LD 109 resonate. It is also possible to align on the same plane in the vessel direction. In the fifth embodiment, the first side surface 803 is a vertical surface with respect to the first flat surface portion 801, but the first side surface 803 is not necessarily vertical with respect to the first flat surface portion 801. The internal angle θ1 may be 90 degrees or more. When the inner angle θ1 is 90 degrees or more, wire bonding to the blue-violet LD 109 is easier than when the inner angle θ1 is 90 degrees.

  By constructing the multi-wavelength semiconductor laser device in this way, it becomes possible to bring the two laser emission points 219 and 221 of the two-wavelength LD 107 closer to the emission point 223 of the blue-violet LD 109 on the vertical cross section with respect to the resonator direction. Thus, it is possible to reduce the size of the optical system and to obtain a multiwavelength semiconductor laser device excellent in heat dissipation.

Embodiment 6 FIG.
10 and 11 are schematic views showing the structure of a multiwavelength semiconductor laser device according to another embodiment 6 of the present invention. FIG. 10 is a schematic cross-sectional view of the multiwavelength semiconductor laser device of the sixth embodiment, and FIG. 11 is a schematic side view. In the multi-wavelength semiconductor laser device according to the sixth embodiment, the second side wall portion 1003 that is the surface that forms the outer angle θ2 with respect to the second flat surface portion 1001 and the second flat surface portion 1001 of the submount 105, Two-wavelength LD 107 and blue-violet LD 109 are respectively mounted. A signal wiring pattern 1005 is formed on the second plane portion 1001 and the second side wall portion 1003. In the fifth embodiment, since the two-wavelength LD 107 and the blue-violet LD 109 are mounted with junction down, the signal wiring pattern 1005 is formed on the second flat surface portion 1001 and the second side wall portion 1003. In the case of mounting with GND, a GND wiring pattern is formed on the mounting portion. The signal wiring pattern 1005 is connected to the lead pin 111 by the bonding wire 113, and the first back surface n electrode 209 of the two-wavelength LD 107 and the second back surface n electrode 213 of the blue-violet LD 109 are connected to the ground pin 115 by the bonding wire 113. . Other configurations of the sixth embodiment are the same as those of the first embodiment. Furthermore, the multi-wavelength semiconductor laser device according to the sixth embodiment adjusts the mounting position of the blue-violet LD 109 so that the two laser emission points 219 and 221 of the two-wavelength LD 107 and the emission point 223 of the blue-violet LD 109 are in the resonator direction. It is also possible to align them on the same plane.

  By constructing the multi-wavelength semiconductor laser device in this way, it becomes possible to bring the two laser emission points 219 and 221 of the two-wavelength LD 107 closer to the emission point 223 of the blue-violet LD 109 on the vertical cross section with respect to the resonator direction. Thus, it is possible to reduce the size of the optical system and to obtain a multiwavelength semiconductor laser device excellent in heat dissipation.

Embodiment 7 FIG.
FIG. 12 is a schematic sectional view showing the structure of a multiwavelength semiconductor laser device according to another embodiment 7 of the present invention. In the multi-wavelength semiconductor laser device according to the seventh embodiment, the second recess 1201 is formed in the second side wall portion 1003 of the submount 105. The second recess 1201 is formed to have a predetermined distance between the recess side surface 1203 that forms the second recess 1201 and the light from the blue-violet LD 109. The light from the blue-violet LD 109 and the submount 105 are separated from each other by the second recess 1201 at a predetermined interval, and the effect of the submount 105 on the light from the blue-violet LD 109 is determined depending on the mounting position on the submount 105. Can be reduced. Other configurations of the seventh embodiment are the same as those of the sixth embodiment.

  By configuring the multi-wavelength semiconductor laser device in this way, it becomes possible to bring the light emission points 219 and 221 of the two lasers of the two-wavelength LD 107 close to the light emission point 223 of the blue-violet LD 109 on the vertical section with respect to the resonator direction. It is possible to reduce the influence of the submount 105 on the light, reduce the size of the external optical system, and obtain a multiwavelength semiconductor laser device excellent in heat dissipation.

  In each embodiment of the present specification, a multi-wavelength semiconductor laser device is configured by mounting a two-wavelength LD of an infrared laser and a red laser and a blue-violet LD, but the wavelength of each laser is not limited to this. For example, the multi-wavelength semiconductor laser device of the present invention may be configured by combining lasers with three wavelengths of red, green, and blue.

  While the drawings and specification disclose typical preferred embodiments of the invention and use specific terminology, they are used in a general and descriptive sense only, and It goes without saying that it is not intended to limit the scope of the claims described in the book.

105 Submount 107 Two-wavelength LD
109 Blue-violet LD
117 Resonator 201 First Laser Part 203 Second Laser Part 205 Third Laser Part 207 First Substrate 211 Second Substrate 215 Center Line 217 One End Part 219, 221, 223 Light Emitting Point 601 Step 701 Overlapping Part 801 First flat surface portion 803 First side surface 805 First side wall portion 1001 Second flat surface portion 1003 Second side wall portion 1201 Second concave portion 1203 Concave side surface

Claims (10)

A first laser diode having a first laser part that emits light of a first oscillation wavelength and a second laser part that emits light of a second oscillation wavelength on a first substrate;
A semiconductor multilayer structure is formed on the second substrate, and has a third laser part that emits light having a third oscillation wavelength. The resonator of the third laser part has a stacking direction of the semiconductor multilayer structure and A second laser diode formed at a position shifted from the center line in the direction perpendicular to the resonator direction toward the one end;
A submount for mounting the first laser diode and the second laser diode;
The multi-wavelength semiconductor laser device, wherein the second laser diode is mounted on a submount so as to be adjacent to the first laser diode on the one end side. A first laser diode having a first laser part that emits light of a first oscillation wavelength and a second laser part that emits light of a second oscillation wavelength on a first substrate;
A second laser diode having a semiconductor multilayer structure on the second substrate and emitting light of a third oscillation wavelength;
A submount for mounting the first laser diode and the second laser diode;
The first laser diode and the second laser diode are mounted on the submount so as to be adjacent to each other,
The multi-wavelength semiconductor laser wherein the first laser diode is mounted with the resonator side on the submount side, and the second laser diode is mounted with the second substrate side on the submount side. apparatus.   The multi-step according to claim 2, wherein a step is formed in the submount, and the mounting positions of the first laser diode and the second laser diode are different positions on a vertical section with respect to the resonator direction. Wavelength semiconductor laser device.   A multi-wavelength semiconductor laser device, wherein a laser optical axis of the first laser diode and a laser optical axis of the second laser diode are aligned on one plane in a cavity direction.   4. The multiwavelength semiconductor laser device according to claim 3, wherein a part of the first laser diode and a part of the second laser diode overlap each other on a vertical section with respect to a cavity direction. A first laser diode having a first laser part that emits light of a first oscillation wavelength and a second laser part that emits light of a second oscillation wavelength on a first substrate;
A second laser diode having a semiconductor multilayer structure on the second substrate and emitting light of a third oscillation wavelength;
A submount for mounting the first laser diode and the second laser diode;
The submount has a first side wall portion having a first side surface and a first side surface forming an internal angle with respect to the first flat surface portion and the first flat surface portion;
The first laser diode is mounted on the first plane portion, and the second laser diode is mounted on the first side wall portion so that the second substrate side faces the first side surface. A multi-wavelength semiconductor laser device. A first laser diode having a first laser part that emits light of a first oscillation wavelength and a second laser part that emits light of a second oscillation wavelength on a first substrate;
A second laser diode having a semiconductor multilayer structure on the second substrate and emitting light of a third oscillation wavelength;
A submount for mounting the first laser diode and the second laser diode;
The submount has a second side wall portion having a second side surface and an outer angle with respect to the second flat surface portion and the second flat surface portion;
The first laser diode is mounted on the second plane portion, and the second laser diode is mounted on the second side wall portion so that the resonator side faces the second side surface. A multi-wavelength semiconductor laser device.   The second side wall portion of the submount has a recess, and the light from the second laser diode has a predetermined distance from a side surface forming the recess. The multi-wavelength semiconductor laser device described.   9. The multiwavelength semiconductor laser device according to claim 8, wherein the concave portion has a groove shape.   10. The multiwavelength semiconductor laser device according to claim 2, wherein the resonator of the second laser diode is formed in the vicinity of an end portion. 10.

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