Generation and detection of broadband coherent terahertz radiation using 17-fs ultrashort pulse fiber laser

We describe the generation and detection of broadband terahertz radiation using an all-fiber laser. Optical pulses from a mode-locked fiber laser oscillator are compressed using nonlinear and dispersion effects induced in optical fibers, and 17-fs optical pulses with 170-kW peak power are generated at the wavelength region around 1.5 microm. By injecting these pulses into an organic crystal DAST (4-N, N-dimethylamino-4'-N"-methyl-stilbazolium tosylate), broadband terahertz field is radiated at 0.1-25 THz. The frequency region exceeding 20 THz is achieved with a fiber laser for the first time.