Ultrafast nonlinear transparency driven at a telecom wavelength in an organic semiconductor system

Abstract

Ultrafast laser-induced transparency is demonstrated using femtosecond (fs) pump-probe experiments in the organic P3HT:PCBM (donor:acceptor) blend structure. For above band gap pumping, ultrafast transient signals strongly depend on the probe photon energy. Most intriguingly, for below band gap pumping at 0.95 eV, or 1.3 µm at a telecom wavelength, a huge transmission increase up to 30% only during the laser pulse ∼100 fs is observed as a pump-driven, quasi-instantaneous suppression of absorption for the high photon-energy energy probe beam. We attribute the observed laser-driven transparency to dynamic Franz-Keldysh effect, at least one order of magnitude stronger compared to the multiphoton nonlinearities. Our results may be used for development of low-cost, beyond 100 Gbit/s optical switching devices.

Organic Thin Films Deposited by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) for Photovoltaic Cell Applications: A Review

“…Poly(3-hexylthiophene-2,5-diyl) (P3HT) is the most common donor polymer in the OPV cells due to its band gap value of ~1.9 eV [124], high hole mobility (over 0.1 cm 2 /Vs) [38,125,126] and easy solution processability. P3HT films were deposited using MAPLE for PV cells, but their potential use in other applications were also evaluated (ex.…”

Generation of nonlinear polarization to emit terahertz waves in above gap states in GaSb/AlGaSb multiple quantum wells

“…ptical nonlinearity is a key factor in designing various optical devices, such as terahertz (THz) wave emitters, [1][2][3][4][5] ultrafast optical devices, [6][7][8][9][10] and wavelength converters. [11][12][13][14] In general, most materials can show odd-order optical nonlinearity, but materials showing even-order nonlinearity are limited because of their crystal structure centrosymmetry.…”