Near-infrared laser emission from luminescent plastic waveguides

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-1,3,5hexatrienyl)-3-methyl-benzothiazolium perchlorat. The poly(1-vinyl-2-pyrrolidone)-base planar waveguides, 1 cm in length and 50 mum in thickness, doped with 0.5 wt % of the compound have exhibited lasing at 820 nm under transverse nanosecond photoexcitation at 532 nm. Optical feedback is provided by the 4% reflective facets of the cleaved waveguide edges. The threshold for lasing is found, to be 128 +/- 30 muJ/cm(2) (25.5 +/- 5.9 kW/cm(2)). Gain spectroscopy has shown a moderate net modal gain of 2.6 +/- 0.3 cm(-1) (11.3 +/- 1.3 dB/cm) at 820 nm for the pump fluence of 115 muJ/cm(2) (23.1 kW/cm(2)). Our results will open the door to the study and development of compact plastic waveguide lasers and amplifiers operating in the near-infrared region. (C) 2004 American Institute of Physics.