| 摘要 |
Amorphous and crystalline potassium lithium tantalate niobate (KLTN) structures for electro-optic devices. Amorphous regions are formed in KLTN crystal by ion bombardment using light ions (protons, helium etc.) >1 MeV. Amorphous regions (cladding) have a lower refractive index (n) than the crystalline material to define waveguide regions in crystals. Selective bombardment via a metal shadow mask produces produce three dimensional structures for: ring resonators, tunable electro-optic resonators, electroholographic alpha gratings, photonic crystals and modulators. Vertical layers of amorphous/crystalline material form a Bragg grating (Raman-Nath diffraction). KLTN (ferroelectric with oxygen perovskite structure) has a large quadratic electro-optic effect in paraelectric phase above the composition dependent Curie (transition) temperature T<SUB>C</SUB>. Electroholographic gratings consisting of alternating regions of KLTN with differing compositions (different T<SUB>C</SUB>) formed by a selective removal of amorphous material and a regrowth step allow wavelength selective E-O beam steering devices (no n difference at E=0) to be made.
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