| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a device for measuring an optical-absorption coefficient of a sample at a high sensitivity. <P>SOLUTION: A ring-down spectral device uses a wavelength-variable femtosecond soliton pulse light source 1. Pulsed light is input to a looped optical fiber 6 through a first optical transmission path 4 and an optical change-over switch 5. Ring-down pulsed light is input to a homodyne detector 40 through the optical change-over switch 5. Meanwhile, pulsed light transmitting through the first optical transmission path 4 is input to each optical transmission path constituting a second optical transmission path 20, in a branching manner, through an optical directional coupler 8 and a first optical switch element 12. The pulsed light transmitting through the second optical transmission path 20 is input to the homodyne detector 40 as reference light and is synchronously detected. Optical path length of multiple optical transmission paths constituting the second optical transmission path 20 sequentially differs by the length of optical fiber 6, and each of the optical transmission paths can microscopically fluctuate the optical path length. <P>COPYRIGHT: (C)2012,JPO&INPIT |
