Optical displacement sensor with frequency-selective squeezing of the vacuum noise

Electromechanical analogies are used to derive expressions for the electromechanical Z parameters and for the energy spectra of Langevin sources of noise in an lf equivalent of an optical displacement sensor with frequency-selective squeezing of the vacuum noise. The minimum noise temperature of the sensor is estimated. The use of squeezed vacuum fluctuations can improve the noise matching of the sensor and help to achieve the minimum noise temperature even for nonoptimal parameters of the system.