1.9-W quasi-CW from a near-diffraction-limited 1.55-μm InGaAsP-InP tapered laser

1.9-W quasi-CW output power with about 80% of the power in the central lobe is obtained from a 1.55-μm wavelength InGaAsP-InP MQW tapered unstable resonator laser. This power is found to be emitted in a near-diffraction-limited beam.