16 W CW output power from 100-/spl mu/m aperture laser based on quantum well asymmetric heterostructure with lowest internal loss
16 W CW room temperature front facet output optical power and 72% wall plug efficiency were attained in 100-/spl mu/m-aperture laser diodes based on quantum well heterostructure with ultra wide asymmetric waveguide.
Improved catastrophic optical mirror damage level in InGaAs/AlGaAs laser diodes
9.2 W continuous wave (CW) optical power at a heatsink temperature 10/spl deg/C and 12.2 W in a regime with stabilised temperature of the laser chip is demonstrated from a 100 /spl mu/m aperture InGaAs/AlGaAs (/spl lambda/=1.03 /spl mu/m) laser diode with 0.4 /spl mu/m wide GaAs waveguide. Thus, record-high optical power densities of 30 MW/cm/sup 2/ and 40 MW/cm/sup 2/ correspondingly are achieved at the front facet without catastrophic optical mirror damage (COMD).
Grazing incidence optics for wide-field x-ray survey imaging: a comparison of optimization techniques
Discussions of optimizing wide-field x-ray optics, with field-of-view less-than 1.1 degree-squared, have been made previously in the literature. However, very little has been published about the optimization of wide-field x-ray optics with larger field-of-views, which technology could greatly enhanced x-ray surveys. We have been working on the design of a wide-field (3.1 degree-squared field-of-view), short focal length (190.5 cm), grazing incidence mirror shell set, with a desired rms image spot size of 15 arcsec. The baseline design consists of Wolter 1 type mirror shells with polynomial perturbations applied to the baseline design. The overall optimization technique is to efficiently optimize the polynomial coefficients that directly influence the angular resolution, without stepping through the entire multi-dimensional coefficient space. We have investigated optimization techniques such as the downhill simplex method, fractional factorial, and response surface (including Box- Behnken and central composite) design. We have also investigated the use of neural networks, such as backpropagation, general regression, and group method of data handling neural networks. We report our findings to date.