Title :
Y-cut LiNbO3 directional coupler with a self-aligned electrode
Author :
Lee, Sang-Shin ; Oh, Min-Cheol ; Jhee, Yoon-Kyoo ; Shin, Sang-Yung
Author_Institution :
Dept. of Electr. Eng., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea
fDate :
5/1/1994 12:00:00 AM
Abstract :
A 2×2 Y-cut LiNbO3 directional coupler switch using a self-aligned uniform Δβ electrode is fabricated by the proton diffusion method. Our design method makes it possible to form the electrode without the delicate alignment of the electrode pattern mask and optical waveguide. The switching voltage is also reduced due to the enhanced electro-optic efficiency by using the self-aligned electrode. To achieve the initial cross state of the uniform Δβ switch that is essential for low crosstalk, we control the proton diffusion time successively after the proton exchange. The measured crosstalk level of the directional coupler switch is -23 dB~-29 dB and its voltage-length product is as small as 9.6 Vmm
Keywords :
crosstalk; directional couplers; electro-optical devices; electrodes; ion exchange; lithium compounds; optical couplers; optical modulation; optical switches; optical waveguides; 2×2; LiNbO3; LiNbO3 directional coupler; Y-cut; crosstalk level; design method; directional coupler switch; electrode; electrode pattern mask; enhanced electro-optic efficiency; initial cross state; optical waveguide; proton diffusion method; proton diffusion time; self-aligned electrode; switching voltage; voltage-length product; Directional couplers; Electrodes; Fabrication; Optical crosstalk; Optical devices; Optical filters; Optical switches; Optical waveguides; Protons; Voltage;
Journal_Title :
Lightwave Technology, Journal of
