Abstract
We demonstrate fabrication of a periodic structure for quasi-phase-matching (QPM) second-harmonic generation (SHG) in 3,5-dimethyl-1-(4-nitrophenyl) pyrazole (DMNP) by electron-beam (EB) writing. It is found that DMNP loses optical anisotropy and is changed to an amorphous phase by EB irradiation. This indicates that the SHG coefficient is zero at the irradiated part. Periodic structures with 0.5 µm period and 0.5 duty ratio were obtained in channel waveguides at a dose of approximately 5000 µC/cm2.