阅读说明：本技术 带有n面非注入区窗口的半导体激光器 (Semiconductor laser with N-face non-injection region window ) 是由 林涛 穆妍 解佳男 李亚宁 孙婉君 于 2021-07-30 设计创作，主要内容包括：带有N面非注入区窗口的半导体激光器结构,包括从上至下依次设置的P面电极,欧姆接触层,上限制层,上波导层,量子阱,下波导层,下限制层,衬底,N面非注入区窗口一,N面非注入区窗口二,N面电极；本发明带有N面非注入区窗口的半导体激光器结构,通过在较厚的N面衬底制作非注入区窗口来降低前后腔面处的载流子浓度,减少非辐射复合,光吸收相对减少,降低腔面处产生的热量,提高COD阈值,提升器件特性。(The semiconductor laser structure with the N-surface non-injection region window comprises a P-surface electrode, an ohmic contact layer, an upper limiting layer, an upper waveguide layer, a quantum well, a lower waveguide layer, a lower limiting layer, a substrate, an N-surface non-injection region window I, an N-surface non-injection region window II and an N-surface electrode which are sequentially arranged from top to bottom; according to the semiconductor laser structure with the N-surface non-injection region window, the non-injection region window is manufactured on the thicker N-surface substrate to reduce the carrier concentration at the front cavity surface and the back cavity surface, so that non-radiative recombination is reduced, light absorption is relatively reduced, heat generated at the cavity surfaces is reduced, the COD threshold is improved, and the device characteristics are improved.)

1. Semiconductor laser with N face non-injection region window, its characterized in that is including from last P face electrode (1) that sets gradually down, ohmic contact layer (2), go up limiting layer (3), go up waveguide layer (4), quantum well (5), lower waveguide layer (6), lower limiting layer (7), substrate (8), N face non-injection region window one (9), N face non-injection region window two (10), N face electrode (11).

2. The semiconductor laser with the N-surface non-implanted region window according to claim 1, wherein the N-surface non-implanted region window I (9) and the N-surface non-implanted region window II (10) are respectively arranged at two etched ends of the substrate (8), the width range of the N-surface non-implanted region window I (9) and the N-surface non-implanted region window II (10) is 10-500 μm, and the thickness range of the non-implanted region dielectric film is 0.1-5 μm.

3. A semiconductor laser with an N-plane non-implanted region window as defined in claim 1 wherein the material of the N-plane non-implanted region window one (9) is SiO₂Or SiN; the material of the N-surface non-injection region window II (10) is the same as that of the N-surface non-injection region window I (9).

Technical Field

The invention belongs to the technical field of semiconductor lasers, and particularly relates to a semiconductor laser with an N-surface non-injection region window.

Background

The semiconductor laser has the advantages of small volume, low power consumption, long service life, high electro-optic conversion efficiency, wide covered waveband range, low price and the like. Semiconductor lasers are required to have high output power and good beam quality in many application fields, such as pumped solid-state lasers and fiber lasers, laser communication, medical treatment, military and the like.

Because the semiconductor laser has a small volume, how to solve the problem of heat generation of the high-power semiconductor laser is firstly met in the aspect of further improving the output light power of the laser, wherein the most important problem is the problem of cavity surface heat generation. When the semiconductor laser outputs high power, the power density in the quantum well of the active region can reach 10¹⁰W/cm³In order of magnitude, input electric energy cannot be completely converted into optical energy, and partial electric energy can be converted into heat energy, so that the laser is locally overheated, various working performances are degraded, and sometimes sudden catastrophic damage can occur to cause the laser to fail.

The Catastrophic Optical Damage (COD) of the facets is a major cause of sudden failure of edge-emitting semiconductor lasers. Aiming at inhibiting COD from occurring at the cavity surface of the high-power semiconductor laser, the currently common methods mainly comprise: the device comprises a cavity surface passivation treatment technology, a cavity surface coating technology, a non-absorption window technology, a current non-injection area introduced near the cavity surface and a current barrier layer technology. The cavity surface non-injection region technology has become the main structure mode of the high-power semiconductor laser at present due to the characteristics of simple process, easy realization and good process compatibility. The cavity surface non-injection region technology mainly limits the injection of carriers into the cavity surface and reduces the carrier concentration at the cavity surface by respectively introducing a section of current non-injection region near the front cavity surface and the back cavity surface, thereby reducing the non-radiative recombination of the carriers at the cavity surface and improving the COD threshold.

The cavity surface non-injection region technology is mainly implemented on the P surface of the semiconductor laser, and SiO with good insulating property is introduced near the cavity surface₂The dielectric film forms a current non-injection region, so that the temperature rise of the cavity surface can be reduced, and the COD threshold power is improved. But from a heat dissipation perspective, particularly when the die is soldered P-side down on a heat sink during packaging, SiO₂The film layer is not beneficial to heat dissipation due to the poor heat conductivity, the temperature of the cavity surface can be increased, and the technical scheme is not adopted by some researchers at present when the semiconductor laser is manufactured.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a semiconductor laser with an N-surface non-injection region window, based on the prior cavity surface non-injection region technology, the non-injection region window is manufactured on a thicker N-surface substrate to reduce the carrier concentration at the front cavity surface and the rear cavity surface, inhibit the non-radiative recombination process, reduce the carrier induced band gap shrinkage, relatively increase the band gap, relatively reduce the light absorption, reduce the heat generated at the cavity surface and improve the COD threshold.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: the semiconductor laser with the N-surface non-injection region window comprises a P-surface electrode, an ohmic contact layer, an upper limiting layer, an upper waveguide layer, a quantum well, a lower waveguide layer, a lower limiting layer, a substrate, an N-surface non-injection region window I, an N-surface non-injection region window II and an N-surface electrode which are sequentially arranged from top to bottom.

The N-surface non-injection region window I and the N-surface non-injection region window II are arranged at two etched ends of the substrate, the width range of the N-surface non-injection region window I and the N-surface non-injection region window II is 10-500 mu m, and the thickness range of the non-injection region medium film is 0.1-5 mu m.

The material of the first N-surface non-injection region window adopts SiO₂Or SiN; and the material of the N-surface non-injection region window II is the same as that of the N-surface non-injection region window I.

The invention has the beneficial effects that:

the current injection near the front and rear cavity surfaces is reduced through the N-surface non-injection region window, so that the carrier concentration near the cavity surfaces is reduced, and the non-radiative recombination is reduced. Meanwhile, the light absorption of the cavity surface is correspondingly reduced, so that the temperature rise of the front and rear cavity surfaces of the chip is reduced, the COD threshold value is improved, and the degradation of the cavity surface is delayed.

Drawings

Fig. 1 is a schematic diagram of a semiconductor laser with an N-face non-implanted region window of the present invention.

Fig. 2 is a schematic view of a semiconductor laser with an N-face non-implantation region window of embodiment 1.

Fig. 3 is the electron and hole concentration of the active region quantum well at the facet of the cavity in example 1.

Fig. 4 shows the recombination rate of the active region quantum well region along the cavity length direction in example 1.

In the figure, 1-P surface electrode, 2-ohmic contact layer, 3-upper limiting layer, 4-upper waveguide layer, 5-quantum well, 6-lower waveguide layer, 7-lower limiting layer, 8-substrate, 9-N surface non-injection area window I, 10-N surface non-injection area window II and 11-N surface electrode.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1-2, a semiconductor laser with an N-surface non-injection region window, includes a P-surface electrode 1, an ohmic contact layer 2, an upper confinement layer 3, an upper waveguide layer 4, a quantum well 5, a lower waveguide layer 6, a lower confinement layer 7, a substrate 8, an N-surface non-injection region window one 9, an N-surface non-injection region window two 10, and an N-surface electrode 11, which are sequentially disposed from top to bottom.

The N-surface non-injection area window I9 and the N-surface non-injection area window II 10 are respectively arranged at two etched ends of the substrate 8, the width range of the N-surface non-injection area window I9 and the N-surface non-injection area window II 10 is 10-500 mu m, and the thickness range of the non-injection area medium film is 0.1-5 mu m.

The material of the N-surface non-injection region window I9 adopts SiO₂Or a dielectric film with good SiN insulating property; the material of the N-side non-implantation area window two 10 is the same as that of the N-side non-implantation area window one 9.

The working principle of the invention is as follows:

after voltage is applied to the P-surface electrode 1 and the N-surface electrode 11, current is limited to be injected into cavity surface areas at two ends of the laser through the N-surface non-injection area windows I9 and the N-surface non-injection area windows II 10 which are respectively arranged at two ends of the substrate 8, so that the concentration of injected carriers near the cavity surface is reduced, the photon energy density and non-radiative composite heat of the cavity surface area are reduced, and the purposes of protecting the cavity surface of the laser and prolonging the service life of a device are achieved.

Example 1

FIG. 2 shows a window with N-sided non-implanted regions in accordance with example 1 of the present inventionSchematic diagram of a semiconductor laser structure of (1). In example 1, a 808nm semiconductor laser was used as an example, and the cavity length was 2000 μm and the stripe width was 200 μm. The device structure is N-face electrode, SiO₂-N-face non-implanted region window one, SiO₂N-face non-implanted region window two, GaAs substrate, Al_0.5Lower confinement layer of GaAs, Al_0.32GaAs lower waveguide layer, Al_0.12Ga_0.795In_0.085As quantum well, Al_0.32GaAs upper waveguide layer, Al_0.5A GaAs upper limiting layer, a heavily doped GaAs ohmic contact layer and a P-surface electrode.

Wherein the thickness of the N-face electrode is 0.41 μm, the thickness of the GaAs substrate is 100 μm, and the thickness of the SiO layer₂A window of non-implanted region with a thickness of 0.1 μm on N surface and made of SiO₂The thickness of the window II of the N-surface non-injection region is 0.1 mu m, the thickness of the lower limiting layer is 1 mu m, the thickness of the lower waveguide layer is 0.4 mu m, the thickness of the quantum well is 7nm, the thickness of the upper waveguide layer is 0.4 mu m, the thickness of the upper limiting layer is 1 mu m, the thickness of the ohmic contact layer is 0.15 mu m, and the thickness of the P-surface electrode is 0.2 mu m.

Fig. 3(a) and 3(b) show carrier concentrations obtained by simulation in example 1, where the carrier concentrations are electron and hole concentrations in the quantum well of the active region at the facet. Comparing the non-implanted region with the two structures of example 1, the electron concentration at the facet of the non-implanted region is about 6.76X 10¹⁸cm^-3The hole concentration was about 6.9X 10¹⁸cm^-3. Example 1 the concentration of electrons at the cavity surface of the structure was 5.22X 10¹⁸cm^-3Hole concentration of 5.12X 10¹⁸cm^-3. Example 1 after adding an N-face non-injection region window in the structure, the electron concentration was reduced by 22.8% and the hole concentration was reduced by 25.8%.

Fig. 4 shows the recombination rate of the active region quantum well region in the cavity length direction in example 1, which is obtained through simulation, and the structure without non-implanted region is compared with the structure in example 1. The recombination rate at the cavity surface of the structure without the non-injection region is about 1.14 multiplied by 10¹⁸cm^-3Whereas the recombination rate at the cavity surface of the structure of example 1 is about 1.06X 10¹⁸cm^-3And the reduction is 7%.