High Power and Wide Tuning Range External Cavity Wavelength Tunable Laser

This paper reviews our recent activities on the development of high performance full-band wavelength tunable lasers. Our approach utilizes an external cavity configuration, which makes use of a liquid crystal (LC) tunable mirror. We also describe a gap mirror technology for integrating a functional section onto a laser gain chip. A semiconductor optical amplifier, implementing several functions, is integrated on the gain chip used in an external cavity laser, and demonstrated as a high-performance variable attenuator and booster amplifier. Control of the mirror properties through the gap geometry is demonstrated, and further optimization is realized by a gap-filling technique, which increases the output power to above 100 mW across the C-band.