Patent ID: 8953168
Filing Date: 2015-02-10
Classification: G01N

Abstract:
1. An optical sensing device comprising: a source unit configured to generate a polychromatic light beam containing p-polarized beam and s-polarized beam; an interferometric unit, configured to introduce birefringent retardation for generating optical path difference between the p-polarized beam and the s-polarized beam; a SPR sensing unit, configured to receive both p-polarized beam and s-polarized beam and induce a SPR effect to the p-polarized beam associated with a target sample; a detection unit, detecting target sample characteristics by obtaining an interference spectrum of the p-polarized beam and the s-polarized beam from the SPR sensing unit, wherein the interferometric unit comprises a birefringent crystal introducing the optical path difference between the p-polarized beam and s-polarized beam, wherein the interferometric unit further comprises a carrier frequency modulation unit generating oscillation cycles in time domain, so as to introduce a carrier frequency modulation at each wavelength of the p-polarized beam and s-polarized beam, wherein the carrier frequency modulation unit comprises: a liquid crystal variable retarder introducing an extra optical path difference between the p-polarized beam and the s-polarized beam at each wavelength, and an electronic controller adjusting amount of the extra optical path difference introduced by the retarder via controlling an external voltage or current source of the retarder.