Fumio Koyama

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We propose a novel design for multi-wavelength arrays of vertical cavity surface-emitting lasers (VCSELs) using high-contrast gratings (HCGs) as top mirrors. A range of VCSEL cavity wavelengths in excess of 100 nm is predicted by modifying only the period and duty-cycle of the high-contrast gratings, while leaving the epitaxial layer thickness unchanged.(More)
—A tunable bandpass filter is constructed using pat-terned mirrors and a diffraction grating to serve as an optical equalizer. The frequency response of an intensity-modulated light source can be tailored by the passband profile of the equalizer to achieve a larger 3-dB bandwidth. We demonstrate that the 3-dB bandwidth of two LiNO 3 modulators is increased(More)