Generation of optical harmonics in fiber-coupled semiconducting polythiophene films

Optical nonlinearity of semiconducting organic films based on regioregular polythiophene (RR-P3HT) was explored by means of laser frequency conversion in a fiber-coupled experimental setup. Features of harmonic generation in this medium were revealed and compared with other nonlinear media. Possible enhancement of nonlinear susceptibility of RR-P3HT in high-gradient light fields is discussed as well.