DEMONSTRATION OF PHOTONICALLY CONTROLLED GAAS DIGITAL MMIC FOR RF OPTICAL LINKS/

We report design, fabrication, and test of a monolithic GaAs optoelect ronic integrated circuit (OEIC) implementing a broad-band optically dr iven digital/analog radio frequency (RF) interface, The integrated cir cuit (IC) was fabricated using a foundry-compatible enhancement/deplet ion metal-semiconductor field-effect transistor (MESFET) process with no added lithography steps, A single optical fiber carries externally amplitude modulated 0.85-mu m light to the on-chip GaAs metal-semicond uctor-metal interdigitated photodetector. RF as well as simultaneous d igital information encoded at up to 10 Mb/s using a novel waveform set is transmitted over the fiber, The serial digital data is self-clocke d into on-chip registers to control the RF signal chain, which include s a three-bit digital attenuator, The circuit operates in an asynchron ous mode to detect digital and RF on the single optical-fiber input, c ontrol IEF level, and transmit the 2-8-GHz RF to the IC's electrical o utput, Measurements characterizing the RF and digital performance of t he IC as well as a demonstration of the full optoelectronic mixed-mode functioning of the IC are presented.