A widely tunable (Delta lambda/lambda = 7%) micro-mechanical external cavity GaSb-based diode laser (mu ECL) emitting around 2.1 mu m is presented. A micro-machined grating with a rectangular grating profile, which can be tilted electrostatically, is employed as wavelength selective element within the external cavity using a Littrow configuration. An optimized grating profile leads to a high diffraction efficiency in the -1st diffraction order and therefore to a broad tuning range of 152 nm. The maximum output power of the fiber coupled mu ECL system varied only moderately between 22 and 10 mW across the tuning range.

We report on GaSb-based quantum-well diode lasers in a micro-machined external cavity setup using the Littrow configuration. An electrostatically-actuated silicon- grating, optimized to achieve a wide tuning range in the 2.3 mum wavelength range, is used as tuning element. A tuning range of 82 nm could be realized. The maximum output power of the micro external cavity laser (muECL) was above 15 mW over the entire tuning range.

Here we will present a new design for the vertical waveguide structure of (AlGaIn)(AsSb)-based diode lasers leading to a reduced beam divergence in the fast axis of only 44/spl deg/ full width at half maximum (FWHM), compared to 67/spl deg/ FWHM of a standard broad waveguide design. Uncoated ridge-waveguide diode lasers emitting at 2.3 /spl mu/m with a 1000/spl times/64 /spl mu/m/sup 2/ geometry showed a threshold current density of 180 A/cm/sup 2/ (or 60 A/cm/sup 2/ per QW), which is among the lowest values, reported for GaSb-based diode lasers.

We report on GaSb-based quantum-well diode lasers in a micro-machined external cavity setup using the Littrow-configuration. An electrostatically actuated Si-grating, optimized to achieve a wide tuning range in the 2.3mum wavelength range, is used as a tuning element

We report on a widely tunable external cavity GaSb-based diode laser (ECL) in Littrow-configuration. The low (44deg full-width at half-maximum) fast axis beam divergence of the quantum-well diode laser employed allowed an efficient coupling to the external cavity, which resulted in a wide tuning range of 177 nm around the central emission wavelength of 2.30 mum. The maximum output power of the fiber coupled ECL system varied only moderately between 16.5 mW at 2.23 mum and 9 mW at the long-wavelength limit at 2.39 mum

Here we will present a new design for the vertical waveguide structure of (AlGaIn)(AsSb)-based diode lasers leading to a reduced beam divergence in the fast axis of only 44° full width at half maximum (FWHM), compared to 67° FWHM of a standard broad waveguide design. Uncoated ridge-waveguide diode lasers emitting at 2.3 μm with a 1000×64 μm2 geometry showed a threshold current density of 180 A/cm2 (or 60 A/cm2 per QW), which is among the lowest values, reported for GaSb-based diode lasers.

We present results on low beam divergence, low threshold current GaSb-based quantum-well diode lasers emitting in the 1.9 - 2.4 mu m wavelength range. By carefully designing the active quantum-well region, low threshold current densities in the range of 148 to 190 A/cm(2) could be achieved in the entire wavelength range. A novel structure for the epitaxial waveguide was designed and realized experimentally, leading to a reduced beam divergence in the fast axis of 44 degrees full width at half maximum (FWHM), compared to 67 degrees FWHM of a conventional broadened waveguide design. This improvement was achieved without any sacrifice in the laser performance, i.e. the novel laser structure showed the same threshold current I-th and differential quantum efficiency eta(d) as the standard one. Ridge-waveguide lasers employing the new waveguide design and emitting at 2.3 mu m were operated in an external cavity configuration. Due to the improved coupling efficiency of the laser beam into the collimating optic, a wide tuning range of 130 nm could be achieved, limited only by the gain bandwidth of the active material.

Type-I diode lasers based on the (AlGaIn)(AsSb) material family are ideally suited to cover the 2-3 μm wavelength range. In this paper recent progress in terms of output power, beam quality and wavelength tunability is reported, achieved for broad-area and tapered single emitters as well as for linear broad-area laser arrays. Special attention has been paid to the reduction of the fast axis far-field beam divergence, employing improved vertical waveguide laser designs. Furthermore, tapered diode lasers have been developed in order to increase the slow axis beam quality at high output powers. An improved beam quality is of particular importance as many applications, including coupling the laser output into an optical fiber or into an external resonator, require diode lasers with a low beam divergence and a high brightness rather than sheer output power.

Here we will present a new design for the vertical waveguide structure of (AlGaIn)(AsSb)-based diode lasers leading to a reduced beam divergence in the fast axis of only 44/spl deg/ full width at half maximum (FWHM), compared to 67/spl deg/ FWHM of a standard broad waveguide design. Uncoated ridge-waveguide diode lasers emitting at 2.3 /spl mu/m with a 1000/spl times/64 /spl mu/m/sup 2/ geometry showed a threshold current density of 180 A/cm/sup 2/ (or 60 A/cm/sup 2/ per QW), which is among the lowest values, reported for GaSb-based diode lasers.