Second-Harmonic Generation in Thermally Poled Twin-Hole Silica-Glass Fiber: Quasi-Phase Matching with Mercury-Lamp Exposure and its Optimization by Fiber Stretch

The 9th International Conference on the Science and Technology for Advanced Ceramics/The 9th International Symposium on Transparent Oxide and Related Materials for Electronics and Optics (STAC-9&TOEO-9), October 19-21, 2015, Epocal Tsukuba, Ibaraki, Japa

Quasi-Phase-Matched Second-Harmonic Generation in Thermally Poled Twin-Hole Silica-Glass Optical Fiber: Comparison between Mercury Lamp and Excimer Laser Exposures

The 8th International Symposium on Transparent Oxide and Related Materials for Electronics and Optics (TOEO-8), May 13-15, 2013, International Conference Center, Waseda University, Tokyo, Japa

External-fiber-grating vertical-cavity surface-emitting lasers

A Bragg grating in graded-index multimode fiber was coupled to a 0.8-/spl mu/m VCSEL. By using a fiber Bragg grating, the spectral width of the VCSEL decreased to 1/2-1/3 of the initial value, depending on the temperature of the fiber Bragg grating. The minimum spectral width was less than 0.1 nm FWHM. Data transmission using 1-km graded-index multimode fiber was investigated at 700 Mb/s. The power penalty decreased by using the fiber Bragg grating. The decrease was 2 dB for the optimum grating temperature at a bit error rate of 10/sup -9/

Measurements on Low-Frequency Fluctuation in the Laser Diodes

A system for analyzing low frequency light fluctuation is set up with a multi-channel detector and a few results are shown. The multi-channel detector includes a\u27 PCD image sensor which has 256 Fig. 1. Configuration of light analyzing system. sensing elements. The light output of a laser diode is divided into various wavelengths and the light spectral intensities are obtained at various wavelengths. The current noise is also measured. The noises show 1/f spectra. The correlation coefficient between the light and the driving current is calculated from the measured values

1/f Noise in Ceramic Superconductors and Granular Resistors

The authors have measured the current noise in some components of granular structure. The samples are ceramic superconductors, carbon-black graft-polymer resistors, and positive temperature coefficient(PTe) ceramics. All noise spectra are of the 1/! type. The temperature dependence of the noise level is measured and compared with the temperature dependence of the resistance, It is shown that in these components the temperature coefficient of the resistance is related to the noise level as predicted by our temperature fluctuating model