The Technology of Antireflection Coatings on Semiconductor Laser
Date Issued
2005
Date
2005
Author(s)
Chang, Wen-Fa
DOI
zh-TW
Abstract
This essay mainly investigates antireflection (AR) coatings on one facets of laser diodes with nonidentical multiple quantum wells. The AR coating has broadband characteristics to reduce the Fabry-Perot resonance. The light-current curve of the laser diode is measured. With AR coating, the laser diode has no threshold, indicating no oscillation. The spectrum is also measured. It shows that the AR coating could make the device exhibit FWHP (Full Width at Half Power) of 218nm spectral width (1359.45nm ~1577.45nm).
Laser diodes at the lasing wavelength around 1550 nm and 1300 nm, respectively are also AR-coated. After AR coating, their emission spectra have the spectral width of 75nm (1500nm ~1575nm) and 88nm (1250nm~1338nm) , respectively. The AR-coated reflectivity is estimated to be 0.00022 and 0.00021.
The theory of Thin-Film Optical Characteristic Matrix is used to design and simulation the antireflection coatings. InP wafers are used for testing the coating conditions using thermal evaporation. Some suitable optical coating materials are experimented. Also, the problem of heat stress with the optical coating materials is investigated. With proper heating situation, the antireflection coatings on InP wafer has good adhesion under some environment test.
The laser diodes with the nonidentical multiple quantum wells oscillate at dual spectral band. Therefore, the AR coatings need special design to simultaneously suppress the lasing at dual bands. The coating conditions also need careful experiment to prove their functions. After design and experiment, using dual-layer Thin-Film with each layer different from 1/4 wave length, broadband AR coating can be achieved for laser diodes in the optical communication.
Subjects
光學抗反射薄膜
抗反射鍍膜
極低反射率
寬光譜抗反射膜
特徵矩陣
半導體雷射抗反射鍍膜
非對稱多重量子井雷射二極體
半功率全寬
寬光譜
磷砷化銦鎵/磷化銦
砷化鋁鎵銦/磷化銦
共振
氟化鎂
硒化鋅
導納
熱蒸鍍
Thin-Film Optical Antireflection Coatings
AR Coatings
Ultra-low Reflectivity
Broadband Antireflection Coatings
Characteristic Matrix
Semiconductor Laser Antireflection Coatings
Nonidentical Multiple Quantum Wells Laser Diodes
Full Width at Half Power
Broadband Spectrum
InGaAsP/InP
InGaAlAs/InP
Fabry-Perot
MgF2
ZnSe
Admittance
Thermal Coating
Type
thesis