William Bindloss

Detection of ferroelectric domain reversal in KTiOPO4 waveguides

Segmented optical waveguides in KTiOPO4 are fabricated by ion exchange of Rb/Ba for K using molten nitrate salts. The waveguides have been utilized to generate efficient second‐harmonic generation (SHG) of blue light. Four techniques are described which demonstrate that the ion exchange can produce domain reversal in these waveguides, and quasi‐phase matching is utilized to obtain blue light. The experiments involve surface SHG, electrostatic toning, selective etching, and piezoelectric measurements.

Characterization of optical waveguides in KTiOPO4 by second harmonic spectroscopy

Segmented optical waveguides were fabricated in KTiOPO4 by Rb/Ba ion exchange. The waveguides were characterized by measuring, as a function of input optical wavelength, the Bragg‐reflected power, and the intensity of second harmonic (SH) radiation generated within the waveguides. Seven peaks in the SH spectra are assigned to different interactions involving the two lowest‐order spatial modes at the fundamental wavelength and the three lowest‐order spatial modes at the SH wavelength. ‘‘Combined mode’’ SH interactions are found which sum spectrally degenerate fundamental waves which are spatially nondegenerate. Analysis of the spectra is shown to be a convenient method of determining the effective indices of the propagating modes, and these then determine the refractive index depth profile of the waveguide. The relative intensities of the SH peaks are dependent on the depth of the region within the ion‐exchanged area which has a reversal of the ferroelectric polarization direction (reversed domain). In som...

Preparation of single-domain KTiOAsO4 crystals for device application

We report here the crystal growth and characterization of single domain KTiOAsO4 crystals suitable for devices application. The presence of inversion domains were established by various techniques including piezoelectric resonances and electrostatic toning. Techniques for removing these domains from as grown crystals were discussed.