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Register a new user500MHz resonant photodetector for high-quantum-effciency, low-noise homodyne measurement
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We design and demonstrate a resonant-type differential photodetector for low-noise quantum homodyne measurement at 500MHz optical sideband with 17MHz of bandwidth. By using a microwave monolithic amplifier and a discrete voltage buffer circuit, a low-noise voltage amplifier is realized and applied to our detector. 12dB of signal-to-noise ratio of the shot noise to the electric noise is obtained with 5mW of continuous-wave local oscillator. We analyze the frequency response and the noise characteristics of a resonant photodetector, and the theoretical model agrees with the shot noise measurement.
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We present the design and characterisation of a low-noise, resonant input transimpedance amplified photodetector. The device operates at a resonance frequency of $90 ,textrm{MHz}$ and exhibits an input referred current noise of $1.2,textrm{pA}/sqrt{textrm{Hz}}$---marginally above the the theoretical limit of $1.0,textrm{pA}/sqrt{textrm{Hz}}$ set by the room temperature Johnson noise of the detectors $16,textrm{k}Omega$ transimpedance. As a result, the photodetector allows for shot-noise limited operation for input powers exceeding $14,mutextrm{W}$ at $461,textrm{nm}$ corresponding to a noise equivalent power of $3.5,textrm{pW}/sqrt{textrm{Hz}}$. 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.
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