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