The HCA-S-400M series Photoreceivers combine fast photodiodes with the proven and outstanding FEMTO HCA current amplifier technology. The HCA-S-400M is available with either a fast Silicon or InGaAs pin-photodiode located exceptionally close to the input for shortened rise times covering a spectral range from 320 to 1000 nm and 900 to 1700 nm, respectively. The amplifier transimpedance is 5 x 10^3 V/A resulting in a maximum conversion gain of 5 x 10^3 V/W at 1550 nm for the InGaAs model, and 2.7 x 10^3 V/W at 800 nm for the model with Silicon photodiode. The sophisticated DC coupled multistage amplifier design allows measurements from DC to a maximum bandwidth of 400 MHz corresponding to a minimum rise time of 1ns. Due to the low noise design signals with an optical power in the micro Watt range can be detected without the need for further averaging. Different models with free space and fibre-optic input are available.

Applications include spectroscopy, fast pulse and transient measurements, optical triggering, optical front-end for Oscilloscopes, A/D converters and ultra fast lock-in amplifiers.