Titanium-Indiffused Lithium Niobate Waveguides for Quantum Integrated Optical Circuits Working on the Wavelength of 808 nm

The technology for fabrication of titanium-indiffused optical waveguides working on the wavelength of 808 nm was elaborated. Experimental samples of waveguides on z-cut lithium niobate substrates were fabricated. Technological conditions providing their single-mode regime of operation were determined. Optical fiber-to-fiber losses of 1.9 dB for straight 20-mm-long waveguides for TM mode were measured. Modes of waveguides were captured, the propagation and coupling losses were estimated. The elaborated technology for producing waveguides can be further used to fabricate more complex integrated optical circuits operating at a wavelength of 808 nm, which is preferred for quantum applications such as quantum communications and quantum computing.