Tang Ming, Minamide Hiroaki, Wang Yuye, Notake Takashi, Ohno Seigo, Ito Hiromasa
RIKEN ASI, Aramaki, Aoba, Sendai, Japan.
Opt Express. 2011 Jan 17;19(2):779-86. doi: 10.1364/OE.19.000779.
For developing a continuous-wave (CW) tunable Terahertz-wave (THz-wave) source using difference-frequency generation (DFG) in highly nonlinear optical crystals, we proposed and demonstrated a dual-wavelength fiber ring laser system operating around 1060 nm based on wideband chirped fiber Bragg gratings (CFBGs) and semiconductor optical amplifier (SOA). Thermo-induced phase shift along the CFBG produces a very sharp transmission spike therefore two lasing wavelengths with single longitudinal mode operation are oscillating simultaneously within the fiber ring cavity. Due to the inhomogeneous gain broadening property of SOA, the wavelength spacing of our dual-wavelength fiber laser can be continuously adjusted from 0.3 to 9.5 nm. By using this single emitter dual-wavelength fiber laser to pump an organic nonlinear DAST crystal, type-0 collinear phase matching of DFG process can be fulfilled and monochromatic THz wave ranging from 0.5 to 2 THz has been successfully generated.
为了利用高非线性光学晶体中的差频产生（DFG）来开发一种连续波（CW）可调谐太赫兹波（THz波）源，我们提出并演示了一种基于宽带啁啾光纤布拉格光栅（CFBG）和半导体光放大器（SOA）的、工作在1060nm附近的双波长光纤环形激光器系统。沿CFBG的热致相移产生一个非常尖锐的传输尖峰，因此具有单纵模工作的两个激光波长在光纤环形腔内同时振荡。由于SOA的非均匀增益展宽特性，我们的双波长光纤激光器的波长间隔可以在0.3到9.5nm之间连续调节。通过使用这种单发射器双波长光纤激光器泵浦有机非线性DAST晶体，可以实现DFG过程的0型共线相位匹配，并且已经成功产生了范围从0.5到2THz的单色太赫兹波。
