PHOTON-GATED PHOTOCHEMICAL HOLE-BURNING BY 2-COLOR SENSITIZATION IN AN AZIDE POLYMER MATRIX

We report a new type of photon-gated photochemical hole burning system by two-color sensitization via triplet-triplet energy transfer: i.e., zinc 9,18,27,36-tetra(4-tolyl)-tetrabenzoporphine in a glycidyl azide polymer matrix. The hole formation efficiency for two-color excitatio n is 2450 times larger than that for one-color excitation in this syst em. The irradiation intensity dependence of hole depth indicates that the hole formation mechanism in the case of one-color excitation is al so the two-photon sensitization of the decomposition of azide groups a s is for the case of two-color excitation. The thermal stability of bu rnt holes and the temperature dependence of hole formation efficiency are also measured and discussed on the basis of the proposed hole form ation mechanism. The temperature dependence of the quantum efficiency of hole formation is smaller than that for sulfonated tetraphenylporph ine in poly(vinyl alcohol).