Electrooptical Devices
Abstract
The frequency response of an optical guided-wave GaAs interferometer has been measured. The bandwidth of the interferometer biased at a null point was 2.2 GHz, limited by parasites. A small-signal bandwidth of approx 3 GHz can be inferred from this measurement for the case where the interferometer is biased to a linear operating point. This is the highest bandwidth yet reported for a guided-wave GaAs modulator. A surface-emitting GaInAsP/InP laser has been developed in which a monolithically integrated parabolic mirror is used to up- deflect the output of a buried-heterostructure laser. A threshold current as low as 12 mA and a differential quantum efficiency as high as 46 percent have been obtained. GaInAsP/InP distributed feedback lasers have been fabricated with a simple new design in which the grating is etched into the top of a mass- transported buried heterostructure. Single-frequency operation with side modes lower than -32 dB and threshold currents as low as 16 mA has been achieved. Single-mode InP p+-n--n+ slab-coupled rib waveguides capable of phase modulating, TE-polarized, 1.3-micrometer radiation have been fabricated. These guides should prove useful in the fabrication of two-guide coupler switches and interferometric modulators. Keywords: Electrooptical devices, Laser, Surface emitting laser, Interferometer modulator, Lasers buried heterostructure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1985
- Accession Number
- ADA193445
Entities
People
- Dean Z. Tsang
- Richard C. Williamson
Organizations
- Massachusetts Institute of Technology