Semiconductor laser array having high power and high beam quality

Abstract

A semiconductor laser array with features providing good beam quality at high powers, first by employing a laterally unguided diffraction region in which light from a set of waveguides is re-imaged in accordance with the Talbot effect and two arrays of waveguides may be used to provide a spatial filtering effect to select a desired array mode. This provides a laser array with increased power per unit solid angle, and with additional advantages of ability to scale the device up to larger arrays, ability to control the electrical excitation of the device for better optimization, and improved modal discrimination. A second aspect of the invention is the use of a resonance condition in an antiguide array, to produce a uniform near-field intensity pattern and improved coupling and device coherence. This resonance structure may be combined with the Talbot-effect structure to suppress the out-of-phase mode, or the out-of-phase mode may be suppressed by other means, such as by introducing interelement radiation losses or absorption losses in the antiguide array.