METHOD FOR DETERMINATION OF CHANGE OF REFRACTION INDEX OF GASEOUS AND LIQUID MEDIA

摘要

A method for the determination of change of refraction index of gaseous and liquid media is based on measurement of surface plasmon resonance and includes radiation of resonance-sensitive boundary that separates the medium under investigation with smaller optical density and the medium with larger optical density from the side of which radiation takes place with same by intensity S- and P- polarizations, those by means of polarization modulator change each other with frequency, and measurement at that frequency of difference of intensitiesof light reflected from resonance-sensitive boundary near the angle of surface plasmon resonance. The initial signal of polarization difference at given angle is completely compensated with optical method (with compensation Fresnel plate), with registration of the signal of photodetector linearly proportional to change of optical parameters of medium under investigation.