SBIR Phase I: Advanced Silicon-based Photodetectors Using Light Localization and Channeling

This Small Business Innovation Research (SBIR) Phase I project will study the feasibility and analysis of the scientific and technical merit of using combinations of optical modes and surface plasmons (denoted collectively as electromagnetic resonance modes (ER)) to dramatically enhance the performance of photodetectors fabricated on silicon and silicon-on-insulator (SOI) substrates for a variety of applications. Silicon is a very desirable material to fabricate photodetectors on because it is inexpensive and because any readout integrated circuitry can be fabricated alongside the photodetector. Past efforts to develop high bandwidth/high responsivity Si-based photodetectors have been limited by the low light absorption constant of Si. This has led to detectors that have a gain-bandwidth product that is small compared with photodetectors fabricated using direct bandgap materials. Recent theoretical work on combinations of optical modes and surface plasmon modes (i.e., hybrid modes) has clearly demonstrated that combinations of these modes show great promise in enhancing device performance and functionality. The objective of the proposed project is the development of three types of hybrid mode-enhanced Si-based photodetectors for a variety of applications in mature and emerging areas of technology. These devices include hybrid mode enhanced bulk Si metal-semiconductor metal photodetector (MSM-PD), SOI MSM-PD and a Si APD. Successful development of silicon and silicon-on-insulator photodetectors will allow for far greater optoelectronic integration than what is possible now, allowing for the development of practical hybrid systems that integrate photonic and electronic components and in turn reduce costs, increase reliability, reduce size and weight and increase functionality. Applications will be developed including: ER-enhanced hybrid Si and SOI based photodetectors for 850nm wireless communication systems and very short range (VSR) fiber-based communication systems, and ER-enhanced APD detectors with less timing jitter, increased sensitivity and lower bias voltages for single photon detectors and LADAR applications. Besides the impressive market potential of the proposed devices they will also bring about new research areas into controlling light within devices. The techniques of light channeling and localization employed in this project will have far reaching effects on other areas of research and technology besides the applications stated above, such as biological and chemical sensors and devices for medical applications.