The high speed analog optical readout system designed for low temperature experiments

TL;DR

This paper presents an innovative analog optical readout system for low-temperature experiments, enabling efficient, low-noise signal transmission from cryogenic environments with high bandwidth and multiplexing capabilities.

Contribution

The study introduces a novel analog optical transmission method with wavelength multiplexing for cryogenic detectors, improving signal fidelity and transmission capacity in low-temperature experiments.

Findings

Achieves over 150MHz bandwidth at -100°C

Demonstrates low power consumption of 70mW per channel

Enables high-capacity optical multiplexing for cryogenic signals

Abstract

For low-temperature experiments such as liquid xenon dark matter detectors, it is crucial to read out detector signals from cryostats. Traditionally, photoelectrical signals are transmitted from the cryogenic region to the outside using coaxial cables through vacuum feedthroughs on the cryostats. In this paper, we investigate an analog optical transmission method in which the raw electrical signals are converted into optical signals with light intensity linearly proportional to the electrical amplitude, transmitted out of the cryogenic environment through optical fiber, and subsequently converted back into electrical signals by photoelectric devices while preserving the signal waveform. This new approach offers advantages, including low attenuation over long-distance transmission and reduced crosstalk across the feedthroughs. Additionally, the low-temperature optical wavelength multiplexing scheme has been investigated and applied, increasing the transmission capability of a single fiber. At -100 degree Celsius, the proposed analog optical readout system achieves a -3dB bandwidth of larger than 150MHz, a dynamic range of up to 500mV, and a low cryogenic-region power consumption of 70mW per channel, demonstrating its strong potential for low-temperature experiments.