INTERFEROMETER ( VARIANTS ) Russian patent published in 2003 - IPC

FIELD: measurement technology, measurement of optical characteristics of substances, measurement of refractive index of liquid or gas. SUBSTANCE: interferometer has optically coupled source of luminous radiation, reflecting mirror that partially transmits luminous radiation, thin layer with thickness under λ/2 located on one surface of wedge-shaped element whose second surface is reflecting mirror coming in the form of reflecting coat, periodic system incorporating photoelements placed behind reflecting mirror and spectrum analyzer. Wedge-shaped element is fabricated in the form of dish filled with liquid or gas. Angle ϕ included between opposite edges of mentioned dish which carry correspondingly thin partially transmitting layer and reflecting mirror is specified by relation sinϕ = λ/2dn where λ is wave length of light wave; d is period of interference bands which system is formed in thin partially transmitting layer under action of standing light wave; n is refractive index of liquid or gas filling dish. According to one variant above-mentioned dish is flow dish. EFFECT: high accuracy of measurement of absolute value of refractive index of liquid or gas. 2 cl, 2 dwg