Non-steady-state photo-EMF interferometer for detection of mechanical oscillations in transparent scattering objects

Abstract

The operation of an adaptive non-steady-state photo-electromagnetic field (EMF) sensor is studied in an interferometric arrangement including a diffuse scattering object–fiber optic plate. The mechanical oscillations of this plate induce the strains and stresses of the medium, which modulates the phase of the propagating light wave across the plate. The resonant frequencies of the mechanical system and the distribution of the phase modulation amplitude across the plate’s surface are measured. The minimal detectable stress amplitude is estimated.

Fiber-optic vector acoustic receiver based on adaptive holographic interferometer

“…In addition, methods of adaptive interferometry based on two-wave mixing at dynamic hologram recorded in a photorefractive crystal (PRC) make it possible to effectively stabilize the operating point of the optical interferometer without any additional stabilization procedures [9][10][11]. Such technique allows to successfully apply the adaptive interferometers for measuring weak signals under the conditions of influence of external noise factors such as random mechanical impacts, industrial noisy sound and vibrations, temperature or pressure drift, etc [12][13][14][15][16][17][18]. Adaptive interferometers were being already applied for acoustic and hydroacoustic measurements [19][20][21][22][23], including use of scalar-vector methods for detection of an acoustic signal [24,25].…”

Fiber-optic vector acoustic receiver based on adaptive holographic interferometer

“…Such technique allows to successfully apply the adaptive interferometers for measuring weak signals under the conditions of influence of external noise factors such as random mechanical impacts, industrial noisy sound and vibrations, temperature or pressure drift, etc. [12][13][14][15][16][17][18]. Adaptive interferometers were being already applied for acoustic and hydroacoustic measurements [19][20][21][22][23], including use of scalar-vector methods for detection of an acoustic signal [24,25].…”