화학공학소재연구정보센터
Journal of Physical Chemistry, Vol.100, No.8, 2762-2765, 1996
Homogeneous Line-Width of the Different Vibronic Bands of Retinal Absorption in Bacteriorhodopsin by the Hole-Burning Technique
Using the hole-burning technique, resolved vibrational structure was observed in the retinal absorption spectrum of bacteriorhodopsin (bR) in poly(vinyl alcohol) (PVA) film at 10 K with 556 and 632 nm irradiation. The homogeneous line widths of v = 1 and v = 2 vibronic bands are estimated from the deconvolution of the observed spectrum. The absorption maximum is found to shift by 100-200 cm(-1) by using the two excitation wavelengths; resulting from partial site selection due to the contribution of inhomogeneous broadening. The hole width produced by excitation near the zero-phonon band is found to be similar to 1250 cm(-1), which corresponds to a homogeneous width of similar to 600 cm(-1), and the low limit of dephasing time can be estimated as 20 fs. This width is found to be independent of the vibronic band observed.