Near-infrared laser emission from luminescent plastic waveguides

Abstract

We have demonstrated optical gain and laser emission in multimoded plastic waveguides containing a near-infrared-emitting compound, 2-(6-(4-dimethylaminophenyl)-2,4-neopentylene-1,3,5-hexatrienyl)-3-methyl-benzothiazolium perchlorat. The poly(1-vinyl-2-pyrrolidone)-base planar waveguides, 1cm in length and 50μm in thickness, doped with 0.5wt% of the compound have exhibited lasing at 820nm under transverse nanosecond photoexcitation at 532nm. Optical feedback is provided by the 4% reflective facets of the cleaved waveguide edges. The threshold for lasing is found to be 128±30μJ∕cm2 (25.5±5.9kW∕cm2). Gain spectroscopy has shown a moderate net modal gain of 2.6±0.3cm−1 (11.3±1.3dB∕cm) at 820nm for the pump fluence of 115μJ∕cm2 (23.1kW∕cm2). Our results will open the door to the study and development of compact plastic waveguide lasers and amplifiers operating in the near-infrared region.