Limiting number of photochemical holes in an inhomogeneously broadened spectrum

Karl K. Rebane

Gerard A. Mourou

Peter Pokrowsky, W. E. Moerner, F. Chu +1 more

Many investigations have been done on the field of frequency domain optical memories based on photochemical hole burning (PHB). This effect offers an extra dimension for the organization of an optical memory. At cryogenic temperatures several solid state materials such as aggregate color centers in alkali halide crystals exhibit inhomogeneously broadened absorption lines. In such an absorption line permanent narrow holes can be burnt by photochemical processes induced by exposure to intense laser radiation with a wavelength within the inhomogeneously broadened line.

Silvia Volker, R. M. Macfarlane

In inhomogeneously broadened lines, selective photochemistry with narrow band lasers leads to photochemical hole burning. We describe this phenomenon with particular reference to free-base porphyrin (H2P) and chlorin molecules in n-alkane matrices at low temperatures. It is shown that hole burning, which is permanent at low temperatures, can be used to study homogeneous optical dephasing processes as a function of temperature, to measure fast vibronic relaxation, and to assign complex vibronic spectra. Some of the parameters that are important to the potential use of photochemical hole burning for information storage in inhomogeneously broadened lines are measured and discussed.

Игорь Сергеевич Осадько

Peter Pokrowsky, W. E. Moerner, F. Chu +1 more

A current-tuned GaAlAs-diode laser is utilized both to burn and to detect narrow photochemical holes in the inhomogeneously broadened 833-nm zero-phonon line of the R' color center in LiF. Applications for reading and writing data into frequency-domain optical memories based on photochemical hole burning are discussed.