Diffraction gratings can be used to achieve phase matching between the fundamental modes of a slab or confined waveguide. Compared with the usual techniques such as quasi-, Čerenkov, and intermodal phase matching, the matching method used here involves spatial harmonics of the guided electromagnetic field that are generated by the corrugated grating. This grating acts simultaneously as a linear waveguide coupler at both the pump and harmonic frequencies. Using the third spatial harmonic, we report what we believe to be the first observation of grating-assisted phase-matched second-harmonic generation between counterpropagating TM0 modes of an organic waveguide.
© 1995 Optical Society of America
Original Manuscript: December 12, 1994
Published: May 15, 1995
G. Blau, E. Popov, F. Kajzar, J. F. Roux, J. L. Coutaz, and A. Raimond, "Grating-assisted phase-matched second-harmonic generation from a polymer waveguide," Opt. Lett. 20, 1101-1103 (1995)