Abstract

Efficient Second Harmonic Generation (SHG) has been a continuing goal for not only frequency conversion but also for cascading effects such as all-optical switching, spatial solitary waves, etc¹. To date high efficiencies have been demonstrated only in ferroelectric crystals.² However, some poled polymers have even higher nonlinear coefficients and offer ease of processing and low cost fabrication. Several phase-matching techniques have been demonstrated in poled polymers, such as quasi-phase-matching (QPM)^3-6, modal dispersion phase matching^7-9, Cerenkov phase-matching^10-12, and anomalous dispersion phase matching¹³. However, very few experiments have progressed from the slab to the channel waveguide stage. We demonstrate phase-matched SHG in a channel waveguide made of 4-dimethylamino-4’-nitrostilbene (DANS) side-chain polymer. Our SHG figure of merit η=P_2ω/(P_ωL)²=14 %/W-cm² is the highest non-resonant value reported for poled polymers and is competitive with those of the best inorganic crystals¹⁴.

© 1996 Optical Society of America