SPECTRUM MEASUREMENT SYSTEM AND SPECTRAL LINE WIDTH MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a spectrum measurement device and a measuring method thereof that enable a spectral line width to be measured with good reproducibility without requiring particular adjustment even if fluctuations occur in a polarization plane of a laser beam when light made incident passes through a delay optical fiber in the spectrum measurement device.;SOLUTION: There is provided a spectral line width measuring method of measuring a spectral line width from results of spectrum analysis of beat signals, using a self-delay heterodyne method of a laser beam. The spectral line width measuring method includes a step of making a laser beam from a laser light source incident on an optical directional coupler after randomizing polarization conditions of the laser beam by a polarization scrambler.;COPYRIGHT: (C)2016,JPO&INPIT