We present a review of the development of a compact and high-power broadband terahertz (THz) source optically excited by a femtosecond photonic crystal fiber (PCF) amplifier. The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient. Broadband THz pulses of 150 µW extending from 0.1 to 3.5 THz are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 fs and a repetition rate of 52 MHz. A strong saturation effect is observed, which is attributed to pump pulse absorption; a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1 040 nm. A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscopy.
© 2011 Chinese Optics Letters
(060.2320) Fiber optics and optical communications : Fiber optics amplifiers and oscillators
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
(060.5295) Fiber optics and optical communications : Photonic crystal fibers
(300.6495) Spectroscopy : Spectroscopy, teraherz
Sources and mechanisms of terahertz radiation
Feng Liu, Xiaokun Hu, Jiang Li, Changlei Wang, Yi Li, Yanfeng Li, Youjian Song, Bowen Liu, Minglie Hu, Lu Chai, Qirong Xing, Chingyue Wang, and Weili Zhang, "Compact and high-power broadband terahertz source based on femtosecond photonic crystal fiber amplifier," Chin. Opt. Lett. 9, 110005- (2011)