Open AccessLaser noise control in the optoacoustical gravitational antenna
Author(s) -
V. A. Krysanov
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1557/1/012044
Subject(s) - physics , noise (video) , optics , discriminator , sensitivity (control systems) , laser , dynamic range , noise spectral density , acoustics , control theory (sociology) , noise figure , electronic engineering , amplifier , optoelectronics , detector , computer science , engineering , control (management) , cmos , artificial intelligence , image (mathematics)
It is shown that the metric sensitivity theory of the OGRAN project contains description of the Fabry-Perot cavity displacement readout scheme proposed by Braginsky. In theories a quality factor defines laser noise. As an alternative, two phenomenological intrinsic controlled parameters of laser noise are proposed to analyze readout resolution: spectral densities of frequency deviations and power random modulation P ( t ) = P 0 [1 + £( t )]. The formula for vibration noise is derived. The new theory of instrumental sensitivity is applied to explain the effect of readout noise rise while increasing digitization time. To reduce the readout threshold signal from real value of 2 · 10 −15 cm/Hz 1/2 to required value of 3 · 10 −16 cm/Hz 1/2 there are proposed actions: 1) to limit temperature drift difference between laser and bar cavity frequencies by value of 250 Hz; 2) to suppress by circuitry means vibration disturbance voltage at the discriminator output while increasing by 20 dB width of feedback frequency range and feedback gain in this range.