METHOD OF DETERMINING AMPLITUDE OF NANOVIBRATIONS FROM SPECTRUM OF FREQUENCY-MODULATED SEMICONDUCTOR LASER AUTODYNE Russian patent published in 2014 - IPC G01R29/04 B82B1/00 

FIELD: physics.

SUBSTANCE: method comprises illuminating an object vibrating at frequency Ω with laser radiation; converting radiation reflected from the object into an electric autodyne signal, decomposing the signal into a spectral series, wherein laser radiation with frequency ω₀ is modulated with frequency Ω, which is equal to the oscillation frequency of the object; matching the initial phases of oscillations of the object and modulation frequency of the laser; measuring the amplitude of the second C₂ and fourth C₄ harmonic of the spectrum of the autodyne signal; using the relationship C₂/C₄(σ) to calculate the value of the argument of a first order Bessel function σ; illuminating a non-vibrating object with the modulated laser radiation; measuring the value of the amplitude of the second C_2cal and fourth C_4cal harmonic of the spectrum of the reflected autodyne signal; using the relationship C_2cal/C_4cal(σ_M) to calculate the value of the argument of a first order Bessel function σ_M; calculating the amplitude of nanovibrations ξ using a certain mathematical expression.

EFFECT: high accuracy of determining amplitude of nanovibrations.

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