High-power strained-layer InGaAs/AlGaAs tapered traveling wave amplifier

Abstract

High power, nearly diffraction-limited cw performance has been obtained from a traveling wave amplifier, fabricated in a strained-layer InGaAs/AlGaAs laser structure, with a laterally tapered gain region and with a cavity-spoiling feature to prevent laser oscillation. The input beam diffracts as it propagates, efficiently filling the tapered active region. For input optical power of 85 mW from a Ti:sapphire laser, total cw output of 1.44 W has been achieved with 1.28 W in a central lobe with width less than 1.2 times the diffraction limit at 977 nm wavelength. Only 15 mW of power incident on the amplifier was sufficient to provide 1 W output into the central lobe.