Futoshi Yamamoto

Zero-chirp broadband Z-cut Ti:LiNbO/sub 3/ optical modulator using polarization reversal and branch electrode

In this paper, a novel zero-chirp Z-cut LiNbO/sub 3/ optical modulator using ferroelectric polarization reversal and a branch electrode is proposed. The optical modulator with a Ti-diffused optical waveguide had a very small chirp parameter, which was less than 0.02. The performance showed a preferable 10-Gb/s eye opening and bias stability.

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.

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.

Application of microsandblast machining to LiNbO3 wafer surface for broadband modulators

Machining technology for LiNbO3 (LN) wafer surface aiming a mass-production of broadband LN modulators is investigated. Although several manufacturers commercially supply 40G LN modulators, there are many difficulties in mass-production of such broadband LN modulators. For instance, in order to realize sufficiently broadened bandwidth performance, machining of LN wafer surfaces is necessary as demonstrated by ridge-waveguide modulators and devices using very-thin substrates. We focus the study on the machining technology of LN wafers applicable to mass- production based on micro-sandblast techniques. In order to demonstrate effectiveness of the micro-sandblast, 40G LN modulators designed to have a partially thinned substrate along RF-electrodes are experimentally fabricated.