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Vertical cavity surface-emitting lasers were applied to rapid heating of amorphous Si (a-Si) thin films using high-power infrared illumination at a wavelength of 980 nm, allowing for a high heating rate of up to 200°C/sec, temperature control of less than 0.1°C, and temporal resolution of 0.1 sec. The refined temperature control enabled us to accurately investigate the rapidly evolving period of crystallization in a-Si at high speed. The crystallinity and surface morphology were probed using Raman spectroscopy, UV-visible spectroscopy, and atomic force microscopy. The temperature-dependent crystallinity was quantified by fitting the annealing duration time with a sigmoidal curve. Based on the crystallization times in association with the Arrhenius relation, the activation energy for crystallization was calculated to be 2.6 eV, which is in excellent agreement with those obtained for low-temperature solid phase crystallization.

980 nm VCSEL illumination eliminates the organic additives and densifies the laminated multilayered SOFC NiO–YSZ|NiO–ScCeSZ|ScCeSZ|GDC|GDCscaffold in just 2.42 h compared to >100 h needed for the conventional thermal sintering process.

High-power laser contrast is challenging to measure, especially in the real target irradiation conditions. We present a convenient and relatively simple contrast diagnostic technique based on the measurement of target specular reflectivity at full laser power. The reflectivity remains high even at intensities above 10 19 W/cm 2 in the case of a high-contrast prepulse-free laser. On the contrary, the specular reflectivity drops in the case of lower contrast, due to the beam break-up and increased absorption caused by the preformed plasma. The technique was demonstrated using three different laser systems with several contrast conditions: Astra (CLF, RAL), TiS laser at APRI, GIST, and J-KAREN (APRC, JAEA).