Researchers at Riken's Photo Dynamics Research Center in Sendai, Japan, have developed a 0.7- to 2.4-THz, 125- to 430-µm terahertz wave parametric generator (right) that is injection-seeded by an external cavity diode laser to provide a Fourier transform-limited linewidth of 100-MHz-and-wider tunability than previous designs. The generator uses a gain medium of two MgO:LiNbO3 crystals in series to produce outputs as large as 1.3 nJ per pulse with a peak power greater than 200 mW at room temperature.The work was reported in the Jan. 14 issue of Applied Physics Letters.