CdTe Buffered GaAs Thin-Slab IR Waveguide Modulators and T/R Filter
Abstract
Broadband electrooptic modulation and frequency shifting of CO2 lasers using GaAs thin-slab waveguides have been described previously. The performance of an unbuffered GaAs waveguide traveling-wave modulator has been found to yield a sideband power conversion efficiency of 4.5 + or - .0000045 or -43.6 dB for one watt of microwave drive power. This paper presents the performance of CdTe buffered GaAs waveguide modulator and describes the structural parameters that have been modified to gain 5 dB improvement from that provided by unbuffered IR waveguide modulators. CdTe buffered GaAs thin-slab waveguide modulators with very low optical and microwave insertion losses, have been fabricated. The measured single sideband power that can be converted from the CO2 laser input power is -39 dB for one watt microwave driver power, as compared to a measured value of -44 dB from an unbuffered modulator. The output beam quality has also been improved significantly. A transmission/reflection filter designed to separate the sidebands from the carrier has been fabricated and tested. The rejection ratio of carrier power to sideband power is -19 dB. Cadmium tellurides; Gallium arsenides; Waveguide modulators; Carbon dioxide lasers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1989
- Accession Number
- ADA215999
Entities
People
- G. Carrier
- M. Gilden
- P. K. Cheo
- R. M. Wagner
- R. T. Brown
- W. Glueck
Organizations
- Massachusetts Institute of Technology