A low-noise resonant input transimpedance amplified photodetector

Abstract

We present the design and characterisation of a low-noise, resonant input transimpedance amplified photodetector. The device operates at a resonance frequency of $90\text{MHz}$ and exhibits an input referred current noise of $1.2\text{pA}/\sqrt{\text{Hz}}$---marginally above the the theoretical limit of $1.0\text{pA}/\sqrt{\text{Hz}}$ set by the room temperature Johnson noise of the detector's $16\text{k}\Omega$ transimpedance. As a result, the photodetector allows for shot-noise limited operation for input powers exceeding $14\mu \text{W}$ at $461\text{nm}$ corresponding to a noise equivalent power of $3.5\text{pW}/\sqrt{\text{Hz}}$. The key design feature which enables this performance is a low-noise, common-source JFET amplifier at the input which helps to reduce the input referred noise contribution of the following amplification stages.

Published in Review of Scientific Instruments

References in corpus (1)

• Broadband low-noise photodetector for Pound-Drever-Hall laser stabilization