JP-7856895-B2 - Semiconductor laser element

JP7856895B2JP 7856895 B2JP7856895 B2JP 7856895B2JP-7856895-B2

Inventors

小川尚史
大森雅樹

Assignees

日亜化学工業株式会社

Dates

Publication Date: 20260512
Application Date: 20220805

Claims (14)

circuit board and A waveguide including an active layer is provided, and a semiconductor layer portion is disposed on the substrate, Equipped with, The waveguide is, A wide section equipped with a diffraction grating, A narrow section having a waveguide width narrower than the wide section, in which light generated in the active layer propagates in transverse multimode, Includes, The waveguide comprises a first end face including the end face of the narrow portion, and a second end face located on the opposite side of the first end face. The aforementioned wide portion is, A first region is continuously connected to the aforementioned narrow portion, and the waveguide width widens from the first end face side to the second end face side, A semiconductor laser element equipped with the following features.
The waveguide further includes a second region, The second region is continuously connected to the first region. The waveguide width in the second region is constant. The semiconductor laser element according to claim 1, wherein the second region includes the diffraction grating.
The semiconductor layer includes a first semiconductor layer having a first refractive index and a second semiconductor layer having a second refractive index different from the first refractive index. The semiconductor laser element according to claim 1, wherein in the diffraction grating, one or more first protrusions provided on the surface of the first semiconductor layer and one or more second protrusions provided on the surface of the second semiconductor layer are periodically arranged in the direction of light propagation in the diffraction grating.
The semiconductor laser element according to claim 3, wherein the first semiconductor layer is disposed between the active layer and the second semiconductor layer.
The semiconductor laser element according to claim 3, wherein each of the first and second protrusions is arranged parallel to the second end face.
The semiconductor laser element according to claim 3, wherein each of the first and second protrusions is arranged in a convex curve from the first end face side toward the second end face side.
The semiconductor laser element according to claim 6, wherein the tangents to the inner circumference of each of the first protrusions and the tangents to the inner circumference of each of the second protrusions are parallel to the wavefront of the propagating light.
A semiconductor laser element according to any one of claims 1 to 7, wherein 90% or more of the total output of light emitted from the second end face falls within a wavelength range of 0.01 nm to 0.5 nm.
The semiconductor laser element according to any one of claims 1 to 7, wherein the waveguide width of the portion where the diffraction grating is provided is two times or more and four times or less the waveguide width in the narrow portion.
The semiconductor laser element according to any one of claims 1 to 7, wherein the waveguide width in the narrow portion is 15 μm or more and 90 μm or less.
The semiconductor laser element according to any one of claims 1 to 7, wherein the waveguide width of the portion where the diffraction grating is provided is 30 μm or more and 360 μm or less.
The distance from the first end face to the diffraction grating is determined using an integer m, the effective refractive index n efff of each transverse mode, and the wavelength λ 0 of each transverse mode in vacuum, (m+1/4)×λ 0 /n eff A semiconductor laser element according to any one of claims 1 to 7, expressed as follows.
The semiconductor laser element according to any one of claims 1 to 7, wherein the M² factor of the light emitted from the second end face is 5 or more and 50 or less.
Multiple light sources, A diffraction grating for wave multiplexing is provided, Each of the aforementioned plurality of light sources is A semiconductor laser element according to any one of claims 1 to 7, The system comprises a collimating lens provided at the position into which light emitted from the semiconductor laser element is incident, The diffraction grating for wave multiplexing is a light source device that combines light emitted from the plurality of light source units.

Description

This disclosure relates to semiconductor laser devices. In recent years, with the diversification of applications for semiconductor laser elements, there has been a growing demand for transverse multimode semiconductor laser elements, which tend to achieve higher output than transverse single-mode semiconductor laser elements. For example, Patent Document 1 discloses a transverse multimode semiconductor laser element. Japanese Patent Publication No. 2011-151238 This is a schematic top view of a semiconductor laser element according to Embodiment 1 of the present disclosure.Figure 1 is a schematic cross-sectional view of the semiconductor laser device shown in line II-II.Figure 1 is a schematic cross-sectional view of the semiconductor laser device along the III-III line.Figure 1 is a schematic cross-sectional view of the semiconductor laser element along the IV-IV line.This is a schematic cross-sectional view showing one step in the manufacturing method of a semiconductor laser element according to Embodiment 1.This is a schematic cross-sectional view showing one step in the manufacturing method of a semiconductor laser element according to Embodiment 1.This is a schematic cross-sectional view showing one step in the manufacturing method of a semiconductor laser element according to Embodiment 1.This is a schematic cross-sectional view showing one step in the manufacturing method of a semiconductor laser element according to Embodiment 1.This is a schematic top view showing one step in the manufacturing method of a semiconductor laser element according to Embodiment 1.This is a schematic cross-sectional view showing one step in the manufacturing method of a semiconductor laser element according to Embodiment 1.This is a schematic top view of a semiconductor laser element according to Embodiment 2 of the present disclosure.This is a schematic top view of a semiconductor laser element according to Embodiment 3 of the present disclosure.This is a schematic top view of the light source device according to Embodiment 4 of the present disclosure.This graph shows the relationship between waveguide width and the effective refractive index for each transverse mode in the simulation.This graph shows the relationship between the waveguide width and the Bragg wavelength at the location where the diffraction grating is placed in the simulation. Hereinafter, embodiments, modifications, and examples for carrying out the invention of this disclosure will be described with reference to the drawings. The semiconductor laser elements described below are intended to embody the technical concept of the invention of this disclosure, and unless otherwise specified, the invention of this disclosure is not limited to the following. In each drawing, components having the same function may be denoted by the same reference numeral. For convenience, in order to explain the key points or to facilitate understanding, components may be shown separately as embodiments, modifications, or examples, but partial substitution or combination of the configurations shown in different embodiments, modifications, and examples is possible. In the embodiments, modifications, and examples described later, descriptions of matters common to those described above will be omitted, and only the differences will be explained. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially for each embodiment, modification, and example. The size and positional relationships of the components shown in each drawing may be exaggerated in order to clarify the explanation. In this specification, "orthogonal" or "parallel" includes deviations of ±0.1 degrees, respectively. Embodiment 1. Embodiment 1 The semiconductor laser element according to this disclosure comprises a substrate and a semiconductor layer portion disposed on the substrate, the semiconductor layer portion comprising a waveguide including an active layer, wherein the waveguide includes a wide portion comprising a diffraction grating and a narrow portion having a narrower waveguide width than the wide portion and through which light generated in the active layer propagates in transverse multimode, the waveguide includes a first end face including the end face of the narrow portion and a second end face located on the opposite side of the first end face, and the wide portion comprises a first region continuously connected to the narrow portion, the waveguide width widening from the first end face side to the second end face side. The semiconductor laser element of Embodiment 1 and its manufacturing method will be described below with reference to Figures 1 to 5F. As shown in Figure 2, the semiconductor laser element 1 according to Embodiment 1 comprises a substrate 2 and a semiconductor layer 3. The semiconductor layer 3 is disposed on the substrate 2. The semiconductor layer 3 includes a waveguide 50 containing an active layer 30. In this specification,