Laser intensity noise evaluation system for space-based gravitational wave detection

The space-based gravitational wave detection can acquire the source information with larger characteristic mass and scale, forming a complementary scheme ground-based detection, primordial pulsar detection. is based on long-distance laser interference device, which mainly detects signals in frequency range of 0.1 mHz–1 Hz. noise evaluation suppression light system directly affect sensitivity. In this work, low-noise photoelectric very low-frequency intensity test constructed high-precision digital multimeter, software control algorithm programming host computer. be converted into fluctuation current signal by utilizing photodiode, voltage amplified transimpedance circuit. Thus high-frequency components are filtered out passive low-pass filtering, extremely retained. According to definition shot noise, it known that photocurrent injected detector inversely proportional so at least 5 mW chosen for After controlling multimeter through LabVIEW programming, acquisition detected. output subjected fast Fourier transform logarithmic axis power spectral density estimation domain, complete measurement system. Hz band finally obtained. experimental results show lower than 5×10<sup>–5</sup> V/Hz<sup>1/2</sup>; electronics ina 4×10<sup>–5</sup> V/Hz<sup>1/2</sup>. electronic multimeters detectors meet requirements space we built meets needs program, provides an important foundation building