Simultaneous frequency stabilization, wavelength multiplexing and improvement of beam quality using a self-optimizing external cavity diode laser.

The combination of a dense wavelength division multiplexer based on volume Bragg gratings (VBGs) and a subsequent feedback mirror forms an efficient single-stage frequency stabilization and multiplexing system. The laser emission of the connected diode laser sources is automatically forced to amplify the wavelengths with the maximum feedback and the minimum losses, respectively. Therefore, different transversal modes of a single emitter may be linked to different wavelength regions that fulfill the Bragg conditions of the VBGs with high efficiency.

Suppression of cross coupling in an external resonator for a diode laser bar with 19 single emitters.

We present an external cavity in a quasi-Littrow configuration for a diode laser bar with 19 single emitters and the individual spectral stabilization, ranging from wavelengths between 970 and 980 nm corresponding to each emitter. The imaging of the vertical waveguide mode onto a blazed grating acting as a diffractive optical element is realized with a beam transformation system that swaps the vertical and lateral axes. Along with a feedback intensity of <10%, the reduction of the divergence due to a beam expander results in high losses for cross coupling modes.

High-power dense wavelength division multiplexing of multimode diode laser radiation based on volume Bragg gratings.

We present a dense wavelength division multiplexer based on volume Bragg gratings (VBGs) with a channel spacing of Δλ = 1.5 nm. Multiplexing efficiencies of ηSM = 97% have been demonstrated with single-mode, frequency-stabilized diode laser radiation.

Simulation of spectral stabilization of high-power broad-area edge emitting semiconductor lasers.

The simulation of spectral stabilization of broad-area edge-emitting semiconductor diode lasers is presented in this paper. In the reported model light-, temperature- and charge carrier-distributions are solved iteratively in frequency domain for transverse slices along the semiconductor heterostructure using wide-angle finite-difference beam propagation. Depending on the operating current the laser characteristics are evaluated numerically, including near- and far-field patterns of the astigmatic laser beam, optical output power and the emission spectra, with central wavelength and spectral width.

Apodized holographic beam combiners for dense wavelength multiplexing based on Gaussian-beam interference.

The brightness of high-power diode-laser systems can be significantly increased by using dense wavelength-multiplexing technologies. Among these technologies, state-of-the-art volume holographic gratings (VHGs) are suitable wavelength-selective filters for scaling the power of frequency-stabilized high-power lasers. The frequency spacing is limited due to the sidelobes of the spectral filter characteristic.