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From a comparison between the degradation rates, induced by proton and electron irradiations, of the performances of GaAs quantum well based vertical cavity surface emitting laser, we deduce a coefficient of equivalence between the two types of irradiations. This coefficient allows us to calculate the fluence of protons of a given energy which produces the same degradation as a fluence of electrons of a standard energy. We apply the result of this analysis to the degradation of GaAs solar cells, demonstrating that this coefficient allows a quantitative prediction of the degradation induced by a proton irradiation, when the degradation induced by electrons at one energy is known.

We report an efficient continuous wave (CW) laser emission at 559 nm by sum-frequency mixing of the fundamental and first-Stokes fields generated within an Nd:YVO4 self-Raman laser. Intracavity sum-frequency mixing with LiB3O5 (LBO) nonlinear crystal yielded 890 mW of visible yellow-green emission, corresponding to an optical conversion efficiency of 4.9% with respect to the incident pump power; the output power stability over 4 h is better than 5.7%. The laser beam quality M2 factors are 3.65 and 4.13 in both horizontal and vertical dimensions respectively.

We describe a way to obtain the degradation, induced by proton and electron irradiations, of solar cell parameters (short-circuit current, open-circuit voltage and maximum power) versus fluence, directly from the calculation of the characteristics of the cell and of the irradiation-induced recombination centres. The calculation can be performed for any energy of the irradiating particle and for any specific thicknesses and doping levels of the base and emitters. The validity of this approach is illustrated in the case of GaAs cells of different origins and extended to GaInP cells. It will allow us to deduce the degradation of multijunction cells.

We present a laser architecture to obtain continuouswave (CW) light sources at the 589 nm sodium D2 line. A 808 nm diode-pumped a Nd:YLiF 4 (Nd:YLF) crystal emitting at 1053 nm. A part of the pump power was then absorbed by the Nd:YLF crystal. The remaining was used to pump a Nd:YAG crystal emitting at 1338 nm. Intracavity sum-frequency mixing at 1053 and 1338 nm was then realized in a LiB 3 O 5 (LBO) crystal to reach the yellow-orange radiation. We obtained a CW output power of 235 mW at 589 nm with a pump laser diode emitting 17.8 W at 808 nm. Stability of the yellow-orange output power around the 235 mW operation point

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We report a diode-pumped Nd:YVO 4 laser emitting at 880 nm based on the 4 F 3/2 -4 I 9/2 transition for the first time. A power of 1.13 W at 880 nm has been achieved in continuous-wave operation with a fiber-coupled laser diode emitting 28.6 W at 808 nm. Furthermore, intracavity secondharmonic generation in continuous-wave mode has also been demonstrated with a power of 233 mW at 440 nm by using a BiB 3 O 6 (BiBO) nonlinear crystal. The fluctuation of the blue output power was better than 2.3%. The beam quality M 2 value is 1.2. Output powers at 880 nm and 440 nm versus pump power at 808 nm

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