PAM-XIAMEN offers 650nm laser diode (LD) wafer, which emits red visible light. The epi wafer for laser diode 650nm from us is composed of the epi layers: P+ GaAs, P- AlGaInP, undoped AlGaInP, undoped GaInP QW, undoped AlGaInP and N- AlGaInP, deposited on the N type GaAs substrate. Here is the specific 650nm laser diode wafer structure for your reference.
1. Details for 650nm LD Wafer
1.1 650nm Laser Diode Wafer Epitaxial Structure(PAM210622-650LD)
P+ GaAs P>5E19, d=0.15μm
P- AlGaInP and undoped AlGaInP d~1.5μm
Undoped GaInP QW PL:640+-5nm
Undoped AlGaInP and N- AlGaInP , d~2.2μm
N GaAs substrate N=(0.4~4)×10^18 d=350~625μm (100) 10°off <111>A
1.2 650nm Wavelength Emission Material
Wafer material emit 650 nm wavelength highlighted in red circle:
2. About the Laser Diode
The laser diode is essentially a semiconductor diode. According the PN junction material, the laser diode can be divided into homojunction, single heterojunction (SH), double heterojunction (DH) and quantum well (QW) laser diodes. Among all the LD types, quantum well laser diodes have the advantages of low threshold current and high output power, and are the mainstream products currently used in the market.
*Laser Diode Working Principle
The crystal diode is a p-n junction formed by a p-type semiconductor and an n-type semiconductor, and a space charge layer is formed on both sides of the interface, and a self-built electric field is built. When there is no applied voltage, the diffusion current caused by the difference in the carrier concentration on both sides of the laser diode junction is equal to the drift current caused by the self-built electric field, and it is in electrical equilibrium.
*Laser Diode Application
The laser diode has already applied in the fields of military, medical, industrial processing and etc.
3. Challenges in the Preparation of Commercial Laser Diode Wafer
Although the prospects of laser diode wafer are bright, the current key technology and engineering research of the three primary colors of red, green and blue LD materials for laser light sources urgently need to make breakthroughs. PAM-XIAMEN focuses on solving the industrialization problem of red LD, one of the three primary colors, with a clear goal, which is to develop high beam quality, low threshold, long life, low cost red LD, and complete technical reserve for production engineering.
In view of the above goals, the following technical problems need to be solved:
1) Efficient injection of carriers in the quantum well;
2) Suppression of defects in AlGaInP epitaxial materials with high aluminum content;
3) Suppression of optical catastrophe of cavity surface.
To solve these problems, it is necessary to break through the low defect density, high strain, high uniformity, low-cost AlGaInP epitaxial material growth, quantum well intermixing non-absorption window & cavity surface passivation, efficient thermal management of LD package modules, test characterization of LD manufacturing links and other key technologies.
4. 650nm Laser Diode Wafer Usages
Laser diode wafers can be used as a photoelectric switch with excellent performance and reliable quality, which make laser diode efficiency higher than before. Epitaxial wafer for laser diode 650nm is widely used in laser pointers, DVD players, laser marking, laser ranging and so on.