Patent ID: 8488433
Filing Date: 2013-07-16
Classification: G01B,G01D,G11B

Abstract:
1. A modulated signal detecting apparatus for detecting a modulated signal, comprising: a wavelength-variable laser which emits laser light and which is capable of varying oscillation wavelengths; an optical divider which splits the laser light emitted from the wavelength-variable laser into signal light and reference light; a reference light mirror which is arranged on an optical path of the reference light; an interference unit which causes an interference between the signal light that has been modulated and the reference light that has been reflected by the reference light mirror; an interference light detecting unit which detects interference light created by the interference unit and which outputs an interference light detection signal; and a wavelength control signal generating unit which generates an oscillation wavelength control signal for controlling an oscillation wavelength of the wavelength-variable laser based on the interference light detection signal, wherein when ld then an initial optical path difference |ld