Optical spectroscopy techniques, including visible and near infrared (IR) Raman and synchrotron IR methods have been applied to study solid nitrogen at megabar pressures. We find that nitrogen becomes totally opaque above 150 GPa, accompanied by the disappearance of Raman and IR vibrational excitations, while new broad IR and Raman bands become visible. Optical absorption measurements reveal th...

The optical absorption of pure liquid water in the 300-700-nm region has been measured by use of a long (1.5-m) path-length cell. The absorption spectrum coincides well with the edge of previous data in the 200-320-nm region and provides reliable data in the 320-420-nm region that has until now been a region of considerable unreliability. The data obtained for the 420-700-nm region agree quite ...

We numerically demonstrate total absorption in graphene in the near-infrared and visible wavelength ranges by means of critical coupling with guided resonances of a photonic crystal slab. In this wavelength range, there is no plasmonic response in undoped graphene, so the critical coupling is entirely controlled by the properties of the photonic crystal resonance. We discuss the general theory ...

In a study of the quantitative variations of myoglobin in muscles, the need arose for reliable absorption spectra and extinction coefficients of derivatives of both myoglobin and hemoglobin in the visible range. Sufficient data on hemoglobin are available in the literature, but those for myoglobin (1, 2) are conflicting and suggest the need for further study. Therefore, it seemed advisable to p...

To make full use of the solar energy, exploring broad spectrum active photocatalysts has become one of the core issues for photocatalysis. Here we report a novel hexagonal 2H-MoSe2 photocatalyst with ultraviolet (UV)-visible-near infrared (NIR) light response for the first time. The results indicate that the MoSe2 displays excellent photo-absorption and photocatalytic activity in the reduction ...