| 摘要 |
<p>PURPOSE:To sweep the frequency of a light wave with high precision over a wide band range by the wide-band light frequency sweeping device which can sweep the frequency of the light wave over the wide band range. CONSTITUTION:This wide-band light frequency sweeping device is constituted by providing an optical directional coupler 34 which inputs pulse light from an optical pulse modulator 31 in a 1st input port and lets a 1st output port be a port for output to the outside, a loop circuit which has an optical amplifier 33, a frequency shifter 11, and an optical switch 13 interposed between the 2nd output port and 2nd input port of the optical directional coupler 34, and a control circuit 35 which synchronously control the light pulse modulator 31 and optical switch 13, and inserting a variable bandpass filter 12 which has transmission band characteristics for removing natural emitted noise light generated by the optical amplifier 33 and varies in center transmission frequency; and the control circuit 35 performs synchronous control of the variable frequency band-pass filter 12 together with the light pulse modulator 31 and optical switch 13 and varies its center transmission frequency in the unit of a shift frequency given by the frequency shifter 11 according to the circulation of the pulse light.</p> |
