New design rules and experimental study of slightly flared 1480-nm pump lasers

Slightly flared lasers are investigated in order to minimize the longitudinal spatial hole burning impact on the output power saturation of 1480-nm pump lasers. In such a device, the stripe width is narrow at the rear facet for strong single lateral mode operation whereas at the front facet the stripe widens in order to reduce the photon density and as a consequence decrease gain saturation through hole burning effect. We proposed a slightly flared lasers design in order to maintain a uniform photon density along the active stripe. Experimentally, this novel structure exhibits single transverse-mode operation and a 30% output power improvement is obtained compared to the straight active waveguide.