74684-81-4Relevant academic research and scientific papers
Nonlinear absorption of light: Two-photon absorption and optical saturation in metalloporphyrin-doped boric acid glass
Wen,Hwang,Lin,Chen,Wu
, p. 293 - 302 (2003)
The nonlinear absorption of five metal TMPPs (TMPP: tetrakis-(3,4,5-trimethoxyphenyl)porphyrin) doped in boric acid glass are measured with the linear polarized nanosecond laser pulses at different wavelengths by Z-scan; the two-photon absorption (TPA) is dominant in the near infrared, while the characteristic of saturation absorption (SA) is observed close to the Q(0,0) band of porphyrin. The symmetry allowed two-photon π* ← π transitions are suggested to be 1B*1g ← S0 and 1B*2g ← S0, with the cross-sections δ ranging from 25 x 10-50 to 114 x 10-50 cm4 s/photon. We analyze the property of SA with a four-level system, and find that the magnitudes of excited-state absorptivity and saturation intensity are not affected by changing the central metal ion in these experiments.
