Generation of mid- to far-infrared ultrashort pulses in 4-dimethylamino-N-methyl-4-stilbazolium tosylate crystal

Mid- to far-infrared (IR) ultrashort pulses were generated using the organic nonlinear optical crystal 4-dimethylamino-N-methyl-4-stilbazolium tosylate. Frequency downconversion was performed by difference frequency generation (DFG) between the signal and idler pulses from an optical parametric amplifier. By the use of a noncollinear configuration in DFG, the phase matching condition was satisfied for pulse generation in the mid-IR and far-IR ranges. At a noncollinear angle of 0.7 degrees between the signal and idler pulses, IR pulses with spectra extending from 8 to 30 THz were generated. The pulse energy and the temporal duration were estimated to be 300 nJ and 250 fs, respectively, for a signal wavelength of 1540 nm and a noncollinear angle of 0.7 degrees. (C) 2010 Optical Society of America