Using photochemical hole burning

Sakota, K. Maeda, Y Iwamoto, M. Optical recording material using photochemical hole burning. Jpn. Kokai Tokkyo Koho JP 05139048,1993. 

Masciangioli, T., Devanathan, S., Cusanovich, M.A., ToUin, G., and el-Sayed, M.A., Probing the primary event in the photocycle of photoactive yellow protein using photochemical hole-burning technique, Photochem. Photobiol, 72,5, 639-644,2000. 

Incidentally, the photochromic compounds described in the last section cannot be used for photochemical hole-burning experiments. This is because the hole-burning experiment requires a level-selective transition in order to... 

Many tetrazines undergo an irreversible photochemical fragmentation with reasonable quantum yield even at very low temperatures. This fact has been used in several applications of the new spectroscopic technique of photochemical hole burning (HB). In the following sections brief descriptions of the principles of this method with references to applications to tetrazines, especially 3,6-dimethyl-1,2,4,5-tetrazine are given. 

There is another way of measuring of an optical transition which is not based on a coherent optical effect but also employs a coherence property of the laser, namely, its monochromaticity. In the hole-burning technique, as in the OFID method, a cw dye laser is used to create a hole in the absorption spectrum. When this hole is transient, its width, being determined in the low-intensity limit by 2( 7 ) , may be probed by side-band modulation as first demonstrated by Szabo on ruby. When the hole is permanent, as is the case in photochemical hole-burning, the width may be easily measured by means of a narrow-band excitation spectrum as first performed by de Vries and Wiersma on dimethyl j-tetrazine in durene. ... 

We will defer discussion of the proposed mechanism for optical dephasing to Section IX. In a recent paper by Voelker and Macfarlane photochemical hole-burning is used to monitor (supposedly) the vibrational relaxation times of over a dozen excited state modes in porphin. A large variation in vibrational lifetimes ( l-50 ps) was measured whereby no systematic variation as a function of vibrational frequency was found. This result is graphically depicted in Fig. 12. It is not yet clear whether the... 

In previous work it has been shown that the width of the zero-phonon hole (ZPH) in the photochemical hole burned spectrum of the P-band can be used to determine the lifetime of P from its total zero-point level which, incidentally, is a determination not possible by ultra-fast spectroscopy. 

Not only can the technique of persistent photochemical spectral hole-burning (PSHB) be useful for molecular information processing but it has also been discussed for some time in the context of extremely dense frequency-domain optical data storage [59, 60]. 

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