FIELD: spectral analysis. SUBSTANCE: method comprises steps of registering bands of interference system formed due to action of standing light wave upon thin partially transmitting layer in the form of signal of spatial and temporary frequency due to acting upon said thin partially transmitting layer with additional standing light wave for forming on the same layer (being mixing layer) light beatings in radio frequency range. Method is realized at using interferometer having optically matched first and second sources of coherent light irradiations, thin partially transmitting layer, reflecting mirror that partially transmits light irradiation; periodic system having photodetectors, light splitter and spectrum analyzer. It is possible to increase resolution at measuring light fluxes. EFFECT: enhanced resolution at measuring parameters of light irradiation. 2 cl, 1 dwg
