Transform-limited, narrow-linewidth, terahertz-wave parametric generator

An injection-seeded nanosecond terahertz ~THz! wave parametric generator was demonstrated using nonlinear crystals that were pumped by a single frequency Nd:yttrium–aluminum–garnet laser. Spectrum narrowing to the Fourier transform limit ~n51.58 THz, Dn,200 MHz! was achieved by injection seeding the idler wave ~near-infrared Stokes!. This resulted in a THz-wave output power ~900 pJ/pulse, .100 mW peak! approximately 300 times higher than that of a conventional THz-wave parametric generator, which has no injection seeder. This compact system operates at room temperature and promises to be a widely tunable THz-wave source that will compete with free-electron lasers and p-Ge lasers. © 2001 American Institute of Physics. @DOI: 10.1063/1.1370988#