A low-noise, high-gain, and large-dynamic-range photodetector based on a JFET and a charge amplifier

Abstract

We demonstrate a low-noise, high-gain, and large-dynamic-range photodetector (PD) based on a junction field-effect transistor (JFET) and a charge amplifier for the measurement of quantum noise in Bell-state detection (BSD). Particular photodiode junction capacitance allows the silicon N-channel JFET 2sk152 to be matched to the noise requirement for charge amplifier A250. The electronic noise of the PD is effectively suppressed and the signal-to-noise ratio (SNR) is up to 15 dB at the analysis frequency of 2.75 MHz for a coherent laser power of 50.08 µW. By combining of the inductor and capacitance, the alternating current (AC) and direct current (DC) branches of the PD can operate linearly in a dynamic range from 25.06 µW to 17.50 mW. The PD can completely meet the requirements of SNR and dynamic range for BSD in quantum optics experiments.

Keywords

Quantum noise / Bell-state detection (BSD) / Photodetector (PD) / Junction field-effect transistor (JFET) / Charge amplifier

RIGHTS & PERMISSIONS

2024 Zhejiang University Press