Integrated Optical Circuits and Exploratory Materials Research
Abstract
Two types of low-loss single-mode P(+)n(-)n(+) GaAs three-dimensional waveguides have been successfully fabricated and their attenuation coefficients measured. The devices are an optical stripline and a new device, the channel- stop strip guide. The channel-stop strip guides have losses of 0.8 per cm at 1. 06 micrometers and 1.1 per cm at 0.920 micrometers; the losses for the optical striplines are 1.2 per cm at 1.06 micrometers and 1.7 per cm at 0.920 micrometers. A first-order loss calculation has yielded attenuation coefficients within 25 percent of these measured values. Both structures have an n(+) substrate, an n(-) epitaxial layer for guiding, and P(+) regions to laterally confine the light. the p(+) regions have a uniform concentration and are formed by multiple-energy Be(+)-ion implantation. The p(+)n(-) junctions show sharp high-voltage breakdowns at sufficiently high electric fields in the n(-) layer (150,000.V/cm) to enable their use in directional-coupler switches and electroabsorption modulators. The causes for reduced external quantum efficiencies in integrated etched-mesa GaAs-AlGaAs double-heterostructure (DH) lasers have been investigated. The primary loss mechanism appears to be the scattering of light by imperfections in the etched end mirrors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1975
- Accession Number
- ADA029433
Entities
People
- Ivars Melngailis
Organizations
- Massachusetts Institute of Technology