Continuous-Wave Second-Harmonic Generation in Orientation-Patterned Gallium Phosphide Waveguides at Telecom Wavelengths
Konstantinos Pantzas, Sylvain Combrié, Myriam Bailly, Raphaël Mandouze, Francesco Rinaldo Talenti, Abdelmounaïm Harouri, Bruno Gérard, G. Beaudoin, L. Le Gratiet, G. Patriarche, Alfredo De Rossi, Yoan Léger, I. Sagnes, Arnaud Grisard
Abstract
A new process to produce orientation-patterned gallium phosphide (OP-GaP) on GaAs with almost perfectly parallel domain boundaries is presented. Taking advantage of the chemical selectivity between phosphides and arsenides, OP-GaP is processed into suspended shallow-ridge waveguides. Efficient second-harmonic generation from telecom wavelengths is achieved in both Type-I and Type-II polarisation configurations. The highest observed conversion efficiency is 200% W–1 cm–2, with a bandwidth of 2.67 nm in a 1 mm-long waveguide. The variation of the conversion efficiency with wavelength closely follows a squared cardinal sine function, in excellent agreement with theory, confirming the good uniformity of the poling period over the entire length of the waveguide.