Masayuki Motoya

Bright narrowband source of photon pairs at optical telecommunication wavelengths using a type-II periodically poled lithium niobate waveguide

We report on the generation of narrowband photon pairs at telecommunication wavelengths using a periodically poled lithium niobate waveguide that utilizes the nonlinear tensor element d(24) for type-II quasi phase matching. The FWHM bandwidth of the spontaneous parametric downconversion was 1 nm. The brightness of the photon pair source was ~6x10(5)/s/GHz when the pump power was 1 mW. The indistinguishability of the signal and idler photons generated by the degenerate spontaneous parametric downconversion process was studied in a Hong-Ou-Mandel type interference experiment.

Highly efficient wavelength converter for photonic network

Efficient wavelength converter was demonstrated in low-loss adhered ridge waveguide fabricated by dry etching in periodically poled Mg:LN. We obtained highest SHG efficiency of 4500 %/W in telecom band for 32 mm interaction length.

A novel z-cut LiNbO 3 Mach-Zehnder modulator using resonant CPW electrodes with single driving signal for zero-chirp operation

We propose a novel zero-chirp electro-optic modulator using resonant CPW electrodes operated with a single driving signal. The measured chirp parameter was below 0.1 at the frequency of 20.4GHz.

Violet light generation in quasi-phase-matched adhered ridge waveguide

We investigated the properties of Z-cut periodically poled MgO-doped congruent lithium niobate (PPMgCLN) with an adhered ridge waveguide. A second harmonic power of 0.61 mW by third-order quasi-phase matching (QPM) was measured with a Ti:S laser at 808 nm with a normalized conversion efficiency of 680%/W. We examined waveguide dispersion for a first-order QPM device using second harmonic generation (SHG) characteristics in a UV spectrum by third-, fourth-, and fifth-order QPM.

Type II quasi-phase matching in waveguide parametric down converter for quantum information technologies

We demonstrate a quasi-phase matched Type II parametric down converter with adhered ridge waveguide for quantum information technology. The SHG normalized conversion efficiency was 250 %/W at 1.53848 mum for QPM period of 8.0 mum.

Quasi-phase matched difference-frequency generator with adhered ridge waveguide fabricated by dry etching method

We demonstrate 13 mm-long quasi-phase-matched difference-frequency generation device with adhered ridge waveguides fabricated by ECR-RIE dry etching method in periodically poled Zn:LN. The obtained SHG normalized conversion efficiency was 260%/Wcm/sup 2/ in the telecommunication band.

Generation of narrowband photon-pairs in 1550 nm band using Type-II periodically poled lithium niobate waveguide

This study demonstrates the generation of narrowband photon-pairs in 1550 nm band using a periodically poled lithium niobate waveguide utilizing the nonlinear tensor element for the type-II quasi-phase matching. Using a type-0 photon-pair source and narrowband-pass-filters, the narrowband photon-pairs can be also generated.