[Two-photon absorption spectrum].

ABSTRACT

Two-photon absorption (TPA) spectrum of a new organic compound has been directly measured by an approach of using tunable laser from an optical parameter amplifier as an excitation source. The output intensity of optical parameter amplifier can cover a broad spectra range of 400-2,000 nm, and identical intensity in the whole spectral range can be easily adjusted. Therefore, the measurement based on this method is directly and reliable. The experimental results show that this compound exhibit large TPA cross section in a broad spectral range from 750 to 1,100 nm. The profiles of TPA spectrum is quite similar to that of the linear absorption spectra. The peak wavelength of TPA band has a little blue-shift compared with the twice of the peak wavelength of the linear absorption due to the different selection rules for two-photon transition and one-photon transition.