大功率激光二极管的波导结构（waveguide structures for High-power laser diodes）

大功率激光二极管的波导结构（waveguide structures for High-power laser diodes）
1.The Large Optical Cavity (LOC) Concept
The vertical waveguide of a high-power LD consists of a core having a refractive index higher than that of cladding layers.In the core forming the active region, typically a strained quantum well is embedded. An optimized strucutre has to deal essentially with the following:
A. a high confinement factor to reduce the threhold current,
B. a large near-field width to reduce the facet load,
C. a small near-field width to reduce the overall thickness of the epitaxial layers as well as the thermal and series resistances,
D. a large near-field width to achieve a small vertical divergence,
E. low scattering losses,
F. low losses of free-carrier absorption,
G. high doping level to reduce the series resistance,
H. high barriers for the carriers to improve the electrical confinement and therefore the internal effiency and the thermal stability,
I. small barriers between the differenct layers to achieve a low voltage across the diode.
The so-called Large Optical Cavity with broadened waveguide layers allows a simple and good approximation of the near-field distribution to Gaussian one and results in improving LD performance.

[这个贴子最后由wolfgangwoo在 2003/03/16 10:36am 第 2 次编辑]

AlGaAs-waveguide structure for wavelength around 800 nm
The history of high-power LDs starts with the challenge to pump Nd:YAG solid-state lasers. The most important absorption band in Nd:YAG is at 808 nm which perfectly matches the technological possibilities to relize LDs with the established AlGaAs system.Until now the market for high-power LDs was biggest at the wavelength. Not only for high-power solid-state laser systems in materials processing but also for small low-power system used in measurement applications, lots of LDs emitting around 808 nm are needed.

[这个贴子最后由wolfgangwoo在 2003/03/16 11:34am 第 11 次编辑]

AlGaAs waveguide structure for wavelengths for around 800 nm

I think that high power semiconductor laser stack using in material processing is a good research direction. if you know more about the series of diod in deeply. Can you introduce some to us????
thanks a lot !!!

the LD bar at 808 nm

第一幅图 看不到阿！！！

the cooling system for LD bar