Electro-optical properties of Na0.5K0.5NbO3 films on Si by free-space coupling technique
2004 (English)In: New Materials For Microphotonics / [ed] Shin, JH; Brongersma, M; Buchal, C; Priolo, F, 2004, Vol. 817, 225-229 p.Conference paper (Refereed)
We report electro-optic performance of highly polar axis oriented Na0.5K0.5NbO3 (NKN) films grown directly on Pt(100nm)/Ti(10nm)/SiO2/Si(001) substrates by rf-magnetron sputtering. Semitransparent gold electrodes (diameter circle divide = 2 mm) were deposited ontop the NKN films by a thermal evaporation through the contact mask. Processing parameters have been specially optimized to obtain "electrosoft" NKN films with a non-linear fatigue-free P-E characteristics: low remnant P-r = 3.6 muC/cm(2) and high induced polarization P = 26 muC/cm(2) @ 522 kV/cm, and the coercive field E-c = 39 kV/cm. Electro-optical characterization of NKN/Pt/Si films has been performed using waveguide refractometry: a free-space coupling of a light beam into the thin-film waveguide modes. Intensity of TM- and TE-polarized light of 670 nm laser diode reflected from the free surface of NKN film and Au-cladding NKN/PL/Si waveguide was recorded at zero and 30 V (100 kV/cm) bias electric field. Extraordinary and ordinary refractive indices as well as electro-optic coefficient have been determined by fitting these experimental data to the Fresnel formulas. Applying 160 V (530 kV/cm) across the parallel plate NKN capacitor (circle divide = 2 mm, thickness 3 mum), modulation of the reflected light as high as 40% was achieved.
Place, publisher, year, edition, pages
2004. Vol. 817, 225-229 p.
, Materials Research Society Symposium Proceedings, ISSN 0272-9172 ; 817
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-43818ISI: 000224428100033ScopusID: 2-s2.0-5544240874ISBN: 1-55899-767-9OAI: oai:DiVA.org:kth-43818DiVA: diva2:448897
Symposium on New Materials for Microphotonics held at the 2004 MRS Spring Meeting Location: San Francisco, CA Date: APR 13-15, 2004
QC 201110182011-10-182011-10-182011-10-31Bibliographically approved