Terahertz Generation by Optical Rectification in Sugar Crystal

Abstract : We report on THz pulse generation through optical rectification of femtosecond laser pulses in sugar crystals. The sugar crystals were grown from an aqueous solution of caster cane sugar bought in a local grocery. Sugar exhibits rather good nonlinear coefficients (d 23 56 pm/V), but the optical-THz conversion efficiency remains quite weak because of the lack of phase-matching, when pumped by a laser beam of 0.8-μm central wavelength. Nevertheless, sugar availability at a low price makes it a relevant material for trial experiments.