title: Superior optical limiting, stabilization, and spatio-temporal reshaping of ultrashort laser pulses in an opto-stable intrinsic polymer film.
abstract: A chemically modified poly(fluorene-alt-benzothiadiazole) (PFBT) polymer film is reported to exhibit high two-photon absorbing capability and chemical/physical stability upon the action of high-power laser pulses of ~780 nm wavelength and ~160 fs duration. A nonlinear transmission measurement is conducted by varying the input intensity from ~20 to ~600 GW/cm2, the corresponding nonlinear transmission of a ~70 μm thick film is reduced from ~0.8 to 0.18, indicating a superior optical limiting behavior. In the meantime, intensity fluctuation of laser pulses can be significantly reduced after passing through the same film sample. Based on the intensity-dependent nonlinear attenuation mechanism, a straightforward optical reshaping effect on spatio-temporal profiles of the laser pulses has also been demonstrated.
authors.affiliation: Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA. gshe@buffalo.edu
authors.forename: Guang S
authors.initials: GS
authors.lastname: He
authors.forename: Heong S
authors.initials: HS
authors.lastname: Oh
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad