Title :
Singlemode channel waveguides and electrooptic modulators in KTiOPO 4 for the short visible wavelength region
Author :
Rottschalk, Matthias ; Ruske, Jens-Peter ; Hornig, Kay ; Steinberg, Steffen ; Hagner, Gert ; Rasch, Andreas
Author_Institution :
Inst. of Appl. Phys., Friedrich-Schiller-Univ., Jena, Germany
fDate :
10/1/1995 12:00:00 AM
Abstract :
Single-mode channel waveguides at short visible wavelengths have been fabricated in KTiOPO4 by Rb&rlhar2;K ion exchange in mixed melts of RbNO3-KNO3-Ba(NO3)2 . The technological parameters have been chosen by means of theoretical WKB- and “effective index” calculations concerning the singlemode region of the effective channel waveguide index N00 at the given wavelength. Great diffusion anisotropy and small dispersion of the surface refractive index change guarantee singlemode operation of the very same channel waveguide from the blue up to the red. Typical attenuation of about 2.0 dB/cm for TM- and 1.5 dB/cm for TE polarization was obtained at λ=0.5145 μm. Light-induced refractive index changes (photorefractive effect) have been determined as a function of time, wavelength, guided optical mode intensity and temperature. The light-induced effects in Rb&rlhar2;K ion-exchanged channel waveguides in KTiOPO4 are about two orders of magnitude smaller than those in annealed proton-exchanged channel waveguides in LiNbO3. Electrooptic phase modulators have been successfully investigated concerning dynamic Vπ measurements, the electric-optical field overlap and dc-drift phenomena. Design, fabrication and experimental results of integrated-optic Mach-Zehnder-interferometer modulators for short visible wavelengths are presented
Keywords :
Mach-Zehnder interferometers; WKB calculations; electro-optical modulation; integrated optics; ion exchange; light interferometers; optical dispersion; optical fabrication; optical losses; optical waveguides; phase modulation; photorefractive materials; potassium compounds; refractive index; surface phenomena; 0.5145 mum; Ba(NO3)2; KNO3; KTiOPO4; Rb&rlhar2; K ion exchange; Rb-K; RbNO3; RbNO3/KNO3/Ba(NO3)2; dc-drift phenomena; diffusion anisotropy; effective channel waveguide index; effective index calculations; electric-optical field overlap; electrooptic modulators; electrooptic phase modulators; guided optical mode intensity; integrated-optic Mach-Zehnder-interferometer modulators; light-induced refractive index changes; mixed melts; photorefractive effect; short visible wavelength region; short visible wavelengths; single mode channel waveguides; singlemode operation; surface refractive index change; technological parameters; Anisotropic magnetoresistance; Electrooptic modulators; Electrooptical waveguides; Optical attenuators; Optical surface waves; Optical waveguide theory; Optical waveguides; Refractive index; Surface waves; Waveguide theory;
Journal_Title :
Lightwave Technology, Journal of
