Four-layer waveguide devices for second-harmonic generation were investigated by use of a new organic nonlinear optical crystal, isopropyl-4-acetylphenylurea. Blue second-harmonic generation in the form of the Cerenkov-radiation mode and the guided mode (from TE0ω to TE12ω) was demonstrated with a thin-film crystal of isopropyl-4-acetylphenylurea as a substrate. For the relaxation of the phase-matching condition and improvements in conversion efficiency, the thickness-noncritical phase-matching technique was introduced in the organic–inorganic hybrid four-layer waveguide geometry.
© 1997 Optical Society of America
[Optical Society of America ]
H. Yamamoto, T. Sugiyama, J. Jung, T. Kinoshita, and K. Sasaki, "Cerenkov-radiation and guided-mode blue second-harmonic generation in four-layer waveguides using organic thin-film crystals," J. Opt. Soc. Am. B 14, 1831-1837 (1997)