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1. (WO2018105549) WAVELENGTH-SWEPT LIGHT SOURCE, METHOD FOR GENERATING DRIVE DATA FOR WAVELENGTH-SWEPT LIGHT SOURCE, AND OPTICAL DEFLECTOR

Pub. No.:    WO/2018/105549    International Application No.:    PCT/JP2017/043446
Publication Date: Fri Jun 15 01:59:59 CEST 2018 International Filing Date: Tue Dec 05 00:59:59 CET 2017
IPC: H01S 5/06
G01J 9/00
H01S 3/106
H01S 3/131
H01S 5/14
Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
日本電信電話株式会社
Inventors: UENO Masahiro
上野 雅浩
CHIN Meishin
陳 明晨
TATSUMI Shoko
辰己 詔子
SAKAMOTO Takashi
坂本 尊
SASAKI Yuzo
佐々木 雄三
TOYODA Seiji
豊田 誠治
AKAGE Yuichi
赤毛 勇一
YAMAGUCHI Joji
山口 城治
SAKAMOTO Tadashi
阪本 匡
Title: WAVELENGTH-SWEPT LIGHT SOURCE, METHOD FOR GENERATING DRIVE DATA FOR WAVELENGTH-SWEPT LIGHT SOURCE, AND OPTICAL DEFLECTOR
Abstract:
The present invention address the problem of an SS-OCT device that, while the intensity of an interference signal increases as the coherence length of light from a wavelength-swept light source becomes longer, it has been difficult to maintain a long coherence length state over an entire wavelength band for wavelength-sweeping in the case of a conventional wavelength-swept light source in which temporally constant current injection is performed with respect to a gain medium, resulting in a decrease in the PSF intensity which directly impacts the quality of an output image from the SS-OCT device. In a wavelength-swept light source according to the present invention, a long coherence length state of output light is maintained over an entire swept-wavelength band. In correspondence to the wavelength-sweeping, the gain of the gain medium is varied over time and is maintained in a maximum coherence length state. Over the entire swept-wavelength band, the gain of the gain medium is maintained in a near-oscillation threshold state to narrow the unsaturated gain bandwidth of the gain medium. Also disclosed are an SOA current wavelength data acquisition method for driving while maintaining a long coherence length state, a novel coherence length measuring method, and an optical deflector suitable for a wavelength-swept light source.