Microwave applications of photonics circuits

Examples of the use of lightwave circuits to partition airborne systems are presented. The role of lightwave technology in future radar, communication, and electronic warfare system architectures is discussed, with particular reference to the fiber-optic guided missile and aircraft applications. The status of microwave bandwidth lightwave transmitter and receiver circuits operating 1 to 20 GHz is summarized. Laser-current-modulated transmitters are commercially available at 0.83 and 1.3 μm for modulation frequencies <10 GHz with dynamic ranges >125 dB/Hz. LiNbO₃-based integrated optic modulators operating in the laboratory at 1.3 μm can provide dynamic ranges >130 dB/Hz. Optical receivers are commercially available at 0.83 and 1.3 μm with bandwidths to 10 GHz and dynamic range >130 dB/Hz. Laboratory receivers have operated to 20 GHz with similar performance. The noise floor of the optical portion of lightwave links is typically set by laser noise at a noise figure of about 40 dB. The cascaded noise figure of the link, including input and output amplifiers, is set by the gain and noise figure of the input amplifier, by the noise floor of the laser diode, and by the attenuation encountered through the active and passive optical components in the link