Optical-Microwave Interactions in Semiconductor Devices.
Final rept. 17 Jun 77-16 Jun 78,
HUGHES RESEARCH LABS MALIBU CALIF
Pagination or Media Count:
Theoretical and experimental studies of direct-current modulation of semiconductor injection lasers were carried out. The small-signal modulation frequency response of a single-mode laser was measured and found to agree well with the calculation result. Direct modulation of a single-mode laser up to 6 GHz was achieved. Experiments on optical injection locking of a transistor oscillator were carried out. Injection locking was achieved not only at fundamental frequencies but also at various subharmonics with less tolerance in frequency deviation. It is also possible to perform simultaneous switching and phase locking in these oscillators. We have also succeeded in phase locking a GaAs FET oscillator at 7 GHz with an injected optical signal modulated at 3.5 GHz. A novel scheme of carrying out microwave mixing in GaAs FET amplifiers was demonstrated in which one of the signals is fed into the input port of the amplifier while the local oscillator signal is introduced through optical injection and the mixed signal is taken from the output port of the amplifier. Experimental results on the optical switching of GaAs IMPATT diode oscillators is presented. The IMPATT microwave output power can be either enhanced or reduced depending on the bias condition and the microwave cavity tuning.
- Electrical and Electronic Equipment
- Lasers and Masers