Patent ID: 7411675
Filing Date: 2008-08-12
Classification: G01N

Abstract:
1. An optical rotation angle measuring apparatus comprising: a linearly polarized light output section that outputs a linearly polarized light; a phase modulation section that is configured so that fluctuations in modulation characteristic of a first phase modulation unit having a first polarization axis in a predetermined direction and a second phase modulation unit having a second polarization axis orthogonal to the first polarization axis cancel each other, and that modulates a phase of the linearly polarized light output from the linearly polarized light output section; a signal supply section that supplies a modulation signal having a predetermined amplitude for modulating the phase of the linearly polarized light to one of the first and the second phase modulation units; a light intensity detection section that detects an intensity of a light that is emitted from the phase modulation section and transmitted by a sample containing an optically active material that rotates a polarization plane of the light, following a supply of the modulation signal to one of the first and the second phase modulation units by the signal supply section; and an optical rotation angle calculation section that calculates an optical rotation angle by the sample based on the modulation signal supplied from the signal supply section and the intensity of the light detected by the light intensity detection section.