PHOTOTHERMAL INTERFEROMETRIC DEVICE AND CORRESPONDING METHOD Russian patent published in 2020 - IPC G01N21/17 

FIELD: physics.

SUBSTANCE: photothermal interferometric device (1) for detecting molecules in a sample, comprising: Fabry-Perot interferometer (4) with first mirror (5), second mirror (6) and first resonator (7) for holding a sample extending between first mirror (5) and second mirror (6), wherein the mirrors are fixed at a fixed distance from each other, a probing laser device with at least one probing laser (3) for producing the first probing laser beam (8a) and second probing laser beam (8b), exciting laser (2) for directing excitation laser beam (2a) through first resonator (7) of Fabry-Perot interferometer (4) for excitation of said molecule in sample, - wherein Fabry-Perot interferometer (4) comprises third mirror (39), fourth mirror (40) and second resonator (41) for holding sample, extending between third (39) and fourth (40) mirrors, - first (7) and second (41) resonators of Fabry-Perot interferometer (4) are arranged so that the first probing laser beam (8a) intersects with exciting laser beam (2a) in first resonator (7), and the second probing laser beam (8b) does not intersect the exciting laser beam (2a) in the second resonator, photodetector unit (9) comprising first photodetector (44) for detecting the transmitted first probing laser beam (8a), and second photodetector (45) for detecting the transmitted second probing laser beam (8b) and a subtracting device for subtracting a second transmission signal corresponding to the second transmitted probing laser beam from the first transmission signal corresponding to the first transmitted probing laser beam.

EFFECT: technical result is high sensitivity and resistance to noise and external effects.

17 cl, 6 dwg