Integrated Optical Bus Interface Module

Chip-scale integrated optical interface modules that are capable of transmitting digital data and broadband RF analog signals are needed for future military communication platforms and commercial optical fiber networks. The Multiplex/UCSD team proposes a novel monolithically integrated 4-channel WDM transmitter chip, with each channel operating at 10 Gb/s data rate or transmitting broadband (>10 GHz) analog RF signals. The transmitter bandwidth is scalable to 40 GHz per channel. The proposed transmitter module consists of 4-channel electro-absorption modulated lasers (EML), semiconductor optical amplifier (SOA), optical power monitor taps, and a WDM waveguide combiner, all integrated on an InP semiconductor substrate. The proposed chip design is based on materials and device technologies familiar to us, including selective area growth of InGaAsP materials for active and passive optical components, EML laser technology, and analog RF photonics under a DARPA RFLICS program. The output of Phase I of this program will be prototype modules with discrete EML transmitter chip, SOA or variable optical attenuator, and optical power monitors that are fully characterized for optimizing the RF analog and high-speed digital performance, and the design of a multi-mode interference (MMI) waveguide combiner for the WDM channels. In addition, the materials growth, device integration, and packaging layout will be evaluated for selecting the best approach for the development of fully integrated 4-channel transmitter modules in Phase II. The proposed chip-scale optical transmitter module comprising active and passive components is the key to low cost, small size, and low power consumption in the future for optical networks. The technology developed in this project fits Multiplex's continuing marketing roadmap. A broad range of applications are anticipated, including military platforms (RF photonic links, phased array radars, sensor and control signals) and commercial markets (CATV, high speed digital networks, WDM transmitter array for cost sensitive metro/access systems). The ability for different applications to share the same technology platform is the key to cost reduction.