Active Al(x)Ga(1-x)As Devices for Waveguide Circuits.
Abstract
Etched mesa double heterojunction GaAs/GaAlAs lasers were fabricated. Evanescent field coupling into an underlying (Ga/Al)As planar waveguide was achieved with 25% coupling efficiency. Selectively grown 1-bar mesa lasers were also successfully end-fire coupled into curved grown (Ga, Al)As waveguides with 35% efficiency. Waveguide structures capable of channeling light around curves were investigated. Experiments indicate that, with current technology, an optimum radius of curvature is in the 1.27 to 2.54 mm (50 to 100 mil) range. Below 1.27 mm, radiation losses were found to increase very rapidly. (Ga, Al)As active devices compatible with monolithic laser sources were developed. A new structure design, which includes a thin (approx. 3000 A) GaAs cap, permits the fabrication of electroplated Pt Schottky barrier pads without significantly increasing the optical losses in the 8500 to 9000 A wavelength range. Electrooptic directional coupler switches were made. A 17 dB extinction ratio in the coupled channel was measured at a reverse bias voltage of -25 V. Single-line, metal-gap modulators were also demonstrated with a modulation depth of 88% at a peak voltage of -25 V. These types of devices were successfully integrated with a 90 deg curved section of an ion-milled rib waveguide with a radius of curvature of 1.016 mm (40 mils). The major source of loss was the curve itself, which accounted for 17 dB of attenuation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1977
- Accession Number
- ADA047194
Entities
People
- A. R. Reisinger
- D. W. Bellavance
- J. C. Campbell
- K. L. Lawley
Organizations
- Texas Instruments