In this paper, the new structure of 980nm VCSEL was designed and fabricated in order to
improve thermal problem and photo-electricity characteristic. From the point of view reduced
equivalent resistance, P-side electrode was designed as intra-cavity contact structure. The VCSEL with
conventional flip bottom emission structure and intra-cavity contact structure have been fabricated
with the same aperture and tested comparatively. the new structure has a differential resistance of 21Ω,
but the conventional structure has a differential resistance of 25.5Ω. The tested results showed that this
new-type structure VCSEL is expected to improve the thermal characteristics of the device and the
Wet etching process is a key technology in fabrication of VCSEL and their array in order to
improve opto-electric characteristics of high-power VCSEL, devices with multi-ring distribution hole
VCSEL is fabricated. The H3PO4 etching solution was used in the wet etching progress and etching
rate is studied by changing etching solution concentration and etching time. The optimum
technological conditions were determined by studying the etching morphology and etching depth of
the GaAs-VCSEL. The tested results show that the complete morphology and the appropriate depth
can be obtained by using the concentration ratio of 1:1:10, which can meet the requirements of
GaAs-based VCSEL micro- structure etching process.
Wet-oxidation experiments in a nitrogen environment at high temperatures are conducted to improve the photoelectricity performance of the 850nm VCSELs. It is very important to accurately control the oxidation aperture.We have carried out upon the wafer of VCSELs with the same structure by changing the furnace temperature and oxidation time, then micro-probe analyses have been examined at different oxidation depth by scanning electron microscope (SEM) and by X-ray. Oxidation products are examined at different oxidation depths of oxidation layer and each component content is analyzed, we get the law of the wet-oxidation. The oxidation process thermal stability and precision can be improved by lowering the oxidation temperature and prolonging the oxidation time.
All-dielectric film narrow band filter is widely used in laser system owing to its excellent optical capability,
manufacturability and environmental adaptability. But 905nm infrared semiconductor laser system have large divergence
angel so we designed entrance light cone angle 905nm narrow band filter. And center wavelength shift, due to entrance
light cone angle, affects its spectral selective power seriously. In order to reduce these impacts, an informal dielectric
film narrowband filter is designed. Changes of transmission characteristics with oblique incidence of Gaussian beam of
uneven illumination are analyzed. The relationship between the angle of incidence and the central wavelength shift
quantificational are Solved. A ± 30 ° incident 905nm narrowband filter was fabricated. Between 880nm and 950nm, the
average transmittance is above 90%, and at the cut-off band the average transmittance is below 1%.