Electrooptical Devices
Abstract
A mass-transport phenomenon has been utilized to achieve GaInAsP/InP buried-heterostructure (BH) lasers. This novel technique is considerably simpler and more easily controlled than those previously reported, and has resulted in BH lasers with threshold currents as low as 9.0 mA. The technology for fabricating laser diodes, detectors, and optical waveguides in GaInAsP/InP epitaxial wafers requires the use of suitable etching techniques for providing smooth, damage-free surfaces of precision pattern geometries and for the preferential and reproducible removal of specific layers. It has been found that a 1 H(2)SO(4):1 H(2)O(2):10 H(2)O room-temperature solution etches (100) Ga(0. 27)In(0.73)As(0.03)P(0.37) (lambda = 1.3 micron) at a very constant etch rate of 1000 A/min. Other ratios of H(2)SO(4):H(2)O(2):H(2)O should prove useful as slow selective etches for GaInAsP in a variety of applications. Three-guide optical couplers consisting of slab-coupled rib-type guides have been fabricated on GaAs. Their behavior closely approximates that predicted using an effective- index analytic method. Couplers of this type should prove useful as replacements for Y-type power dividers and combiners, especially in cases where waveguide bends would result in unacceptable losses. GaInAsP diode lasers with a proton- isolated modulator have been operated with full on/off modulation at rates of 3 GHz. Both the gain and loss are actively varied in the modulator in order to Q- switch the laser.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1983
- Accession Number
- ADA197070
Entities
People
- Dean Z. Tsang
- Richard C. Williamson
Organizations
- Massachusetts Institute of Technology