High peak power, sub-ps green emission in a passively mode locked W-cavity VECSEL.

We report on the experimental results of a passively mode-locked vertical external cavity surface emitting laser (VECSEL), implemented in a W-cavity configuration, using a lithium triborate (LBO) crystal for intra-cavity second harmonic generation (SHG) at 528 nm. The W-cavity configuration allows separation of the crystal from the semiconductor saturable absorber mirror (SESAM), enabling independent control over the Gaussian beam sizes at the crystal, chip, and SESAM. This optimized cavity demonstrated a second harmonic pulse width of ~760 fs at a frequency of 465 MHz and 230 mW average output power, resulting in a peak pulse power of 580 W.

High Verdet constant of Te20As30Se50 glass in the mid-infrared.

Magneto-optical properties of tellurium-arsenic-selenium glass (${{\rm Te}_{20}}{{\rm As}_{30}}{{\rm Se}_{50}}$Te20As30Se50) were measured and analyzed. A Verdet constant of 15.18 rad/T/m at 1950 nm with the figure of merit of more than 8.72 rad/T, which is the highest value reported in glass materials at this wavelength, was measured. Compared to other chalcogenide glasses, such as ${{\rm Ge}_{10}}{{\rm Se}_{90}}$Ge10Se90 and ${{\rm Ge}_{25}}{{\rm As}_{15}}{{\rm S}_{60}}$Ge25As15S60, ${{\rm Te}_{20}}{{\rm As}_{30}}{{\rm Se}_{50}}$Te20As30Se50 glass exhibits higher Verdet constants, broader mid-infrared transparency window, and longer infrared absorption edge, making it a very promising material to fabricate magneto-optical devices for mid-infrared applications.

Generation of high-power spatially structured beams using vertical external cavity surface emitting lasers.

In this paper, we demonstrate the generation of high-power and spatially structured beams using vertical external cavity surface emitting lasers (VECSEL). At the fundamental wavelength, an intracavity mode-control element is first employed to generate a range of Hermite-Gaussian (HG) modes in a linear cavity. The same HG modes are then excited and frequency doubled in a V-cavity geometry to generate a rich variety of high-power spatially structured beams. The results compare well with our numerical modeling.

Tunable type II intracavity difference frequency generation at 5.4 µm in a two chip vertical external cavity surface emitting laser.

We report on the generation and experimental demonstration of intracavity type II difference frequency generation in a two chip InGaAs/GaAs vertical external cavity surface emitting laser. The presented two chip cavity provides two orthogonally polarized, independently tunable, high-intensity lasing modes with emissions around 970 and 1170 nm. A silver thiogallate nonlinear crystal is inserted in the common collinear folded region of the cavity to generate output in the mid-IR spectral band. The independent tunability of each fundamental color allows for more than 100 nm of tuning around a 5.4 µm difference frequency generated signal with a CW output power in excess of 5 mW.

Tunable type II intracavity sum-frequency generation in a two chip collinear vertical external cavity surface emitting laser.

We report on the generation and experimental demonstration of intracavity type II sum-frequency generation (SFG) in a two chip InGaAs/GaAs vertical external cavity surface emitting laser cavity. The demonstrated two-chip cavity generates two orthogonally polarized, independently tunable, high-intensity intracavity lasing modes at different colors. Using a lithium triborate nonlinear crystal in the common collinear folded cavity region, high output power in the blue-green band is generated. Wavelength tuning with CW output powers in excess of 750 mW is demonstrated. By independent wavelength tuning of each fundamental color, tunable SFG output around 490 nm is reported.