Narrow-linewidth, electro-optically tunable InGaAsP-Ti:LiNbO3 extended cavity laser

Abstract
We report an electro‐optically tunable, single‐frequency extended cavity laser with a linewidth of less than 60 kHz. The laser consists of a 1.5‐μm InGaAsP gain medium and an electro‐optically tunable, narrow‐band Ti:LiNbO3 wavelength filter (Δλ≊12 Å). Electro‐optic tuning over at least 70 Å and single‐frequency operation with output power of more than 1 mW have been demonstrated. The laser linewidth was measured by beating the laser against a 1.523‐μm HeNe laser.