公开(公告)号：US20230333006A1

公开(公告)日：2023-10-19

申请号：US18028962

申请日：2020-09-28

Applicant: JASCO CORPORATION

Inventor： Masaru SHIMIZU ,  Jun KOSHOBU

IPC: G01N21/19 ,  G01N21/35

CPC classification number: G01N21/19 ,  G01N21/35 ,  G01N2201/06113 ,  G01N2201/0683

Abstract: A circular dichroism measurement apparatus includes a laser light source (QCL) capable of sweeping a wavenumber of a laser light in an infrared wavenumber range containing at least one peak of the sample; a sample chamber where the sample is disposed; a photoelastic modulator that modulates a polarization state of the laser light before or after the laser light of a specific wavenumber in a wavenumber sweep transmits the sample; a detector that detects a variation in intensity of the laser light which transmitted the sample and of which its polarization state is modulated; and a signal processing device that extracts an alternating-current component (AC) that synchronize with a modulation frequency and a direct-current component (DC) from a detected signal of the detector, and calculates a value of infrared circular dichroism of the sample based on a ratio (AC/DC) of the AC and DC.