Accession Number : ADA318865
Title : High Performance Ultrafast Photodetectors.
Descriptive Note : Annual rept. Jun-Oct 96,
Corporate Author : BOSTON UNIV MA
Personal Author(s) : Unlu, M. S.
PDF Url : ADA318865
Report Date : OCT 1996
Pagination or Media Count : 5
Abstract : We report spectral and high-speed measurement results on resonant cavity enhanced (RCE) Schottky photodiodes. The Schottky metal contact is semi-transparent and provides the top mirror reflectivity. We demonstrated by simulations that the detector responsivity can be optimized by using a dielectric coating on top of the metal contact. The novel concept of combining a dielectric impedance matching layer with the semi-transparent metal mirror drastically improves the expected quantum efficiency of RCE Schottky photodiodes. Simulations in GaAs/InGaAs material system predicted more than 70% quantum efficiency for an absorbing region of O.13um. The devices were fabricated by using a microwave compatible process. On-wafer high-speed measurements yielded a 18 Ps pulse width corresponding to a 3-dB bandwidth of 20 GHz. We also report on our efforts on polarization sensing photodetectors.
Descriptors : *PHOTODETECTORS, POLARIZATION, DIELECTRICS, PULSED LASERS, SEMICONDUCTORS, QUANTUM EFFICIENCY, SCHOTTKY BARRIER DEVICES, OPTICAL STORAGE, PHOTODIODES, CAVITY RESONATORS, METAL CONTACTS, SEMITRANSPARENCE.
Subject Categories : Optical Detection and Detectors
Distribution Statement : APPROVED FOR PUBLIC RELEASE