Energy optical

Wrighton MS (1979) Photoelectrochemical conversion of optical energy to electricity and fuels. Acc Chem Res 12 303-310... 

At temperatures above ca. 1000 K, heat transfer via radiation becomes significant, that is, the heat transfer can occur by optical energy waves (photons) as well as conduction (phonons), with the heat transfer equation expressed by... 

In addition to heat emission, radiative decay processes may also occur, in which light is emitted due to a transition from the lowest excited singlet or triplet state to the ground state (fluorescence or phosphorescence). In order to effect rapid and efficient conversion of optical energy (the laser) to heat, dyes which exhibit low fluorescence and in which excitation primarily involves the singlet states are the most suitable for heat-mode recording.196... 

In such devices the light-absorbing semiconductor electrode immersed in an electrolyte solution comprises a photosensitive interface where thermodynamically uphill redox processes can be driven with optical energy. Depending on the nature of the photoelectrode, either a reduction or an oxidation half-reaction can be light-driven with the counterelectrode being the site of the accompanying half-reaction. N-type semiconductors are photoanodes, p-type semiconductors are photocathodes, and... 

The absorption (A ax 402nm, logs 4.71) and emission (A ax 453, 477nm) maxima, fluorescence quantum yields, and the optical energy of 2,5-bis[5-(4,5,6,7-tetrahydrobenzo[b]thien-2-yl)thien-2-yl]-l,3,4-oxadiazole 20 were studied in dichloromethane <1998CEJ2211>. 

The sensing methods summarized thus far are intended for absorption detection of molecules in the ambient, but molecules (or indeed thin films) on the microresonator surface can also be detected. In particular, if the surface is covered to such an extent that the optical energy absorbed heats the microresonator, the resulting thermal bistability in the frequency-scan response can be used to determine the absorption and/or thickness of the thin-film coating. This and surface characterization by measurement of the thermal accommodation coefficient were described in Sect. 5.5. These methods offer quite precise measurement, provided that certain reasonable and easily implemented assumptions are satisfied. 

In principle, all of the elements of the periodic table can be used to iucorporate foreign ions in crystals. Actually, only a number of elements have been used for optically active centres in crystals in other words, only a number of elements can be incorporated in ionic form and give rise to energy levels within the gap separated by optical energies. The most relevant centers for technological applications (although not the unique ones) are based on ions formed from the transition metal and rare earth series of the periodic table, so we will focus our attention on these centers. 

The raw band pass of an AOTF has a sine squared function lineshape with sidebands, which if ignored, may amount tol0% of the pass optical energy in off-centre wavelengths. This apodization issue is normally addressed by careful control of the transducer coupling to the crystal. 

Ellis AB, Bolts JM, Kaiser SW, Wrighton MS (1977) Study of n-type gallium arsenide- and gallium phosphide-based photoelectrochemical cells. Stabilization by kinetic control and conversion of optical energy into electricity.99 2948-2853... 

---