GaInAs photodiodes as transfer standards for picosecond measurements

GaInAs photodiodes are developed for use as pulsed transfer standards at the optical fibre communications wavelengths. The concept and requirements for a transfer standard photodiode are discussed. The photodiode and mount are theoretically modelled, results indicate that there is an optimum epitaxial layer thickness and diode series resistance for a particular device diameter and mount inductance. Measurements are made of an unoptimised 45 μm diameter device mounted on a prototype reverse terminated coplanar holder. A measured FWHM of 40 ps was obtained at 1146 nm, and the 3 dB frequency response is measured as 10.8 GHz at 1060 nm.