L. Goldberg et al., DIFFERENCE-FREQUENCY-GENERATION OF TUNABLE MIDINFRARED RADIATION IN BULK PERIODICALLY POLED LINBO3, Optics letters, 20(11), 1995, pp. 1280-1282
A bulk, quasi-periodic phase-matched difference-frequency process is d
emonstrated in field-poled LiNbO3. Continuous tunability of output rad
iation in the 3.0-4.1-mu m wavelength range is achieved through gratin
g rotation. A maximum mid-infrared output power of 0.5 mW is measured.