We report on an optical multichannel RAS (Reflectance Anisotropy Spectroscopy) setup capable of measuring at multiple photon energies simultaneously in the spectral range between 1.4 and 5.0 eV at a temporal resolution of up to 30 ms. The setup is specifically designed for time-resolved studies of surface processes (e.g. epitaxial growth). Its accuracy was evaluated on static surfaces by comparison with RAS spectra acquired using a conventional scanning RAS setup. The performance was demonstrated by studying 2D island growth oscillations during GaAs epitaxy with TMGa and AsH 3 or tBAs in metal-organic vapour phase epitaxy (MOVPE).
We manufactured and investigated distributed Bragg reflector ridge-waveguide diode lasers having sixth-order surface gratings and an emission wavelength around 974 nm. The single-mode output power of the lasers with a total length of 4 mm exceeded 1 W. A very small spectral linewidth of 1.4 MHz (3 dB) consisting of a Lorentzian part of 146 kHz and a Gaussian part of 1308 MHz was measured using a self-delayed heterodyne measurement technique.
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