GaSb-based 2.3 µm quantum-well diode-lasers with low beam divergence

There is an increasing interest in room-temperature diode lasers emitting in the infrared wavelength region between 2.0 and 2.5 pm for spectroscopic gas-sensing, medical diagnostics and therapy [1]. For all of these applications, fiber-coupled laser systems are desirable, which call for a laser design with low beam divergente and concomitant high output power.