Near-infrared luminescent polymer waveguide with a 20 dB small-signal gain

Near-infrared optical gain in luminescent polymeric slab asymmetric waveguides has been investigated by use of amplified spontaneous emission. Upon nanosecond photopumping, the waveguides have shown a small-signal gain coefficient of 37.2 +/- 2.1 cm(-1) at 820 nm for a pump fluence of 1.57 mJ/cm(2) (314 kW/cm(2)). The loss coefficient and transparency fluence have been found to be 7.3 +/- 1.0 cm(-1) at 820 nm and 0.14 mJ/cm(2) (28 kW/cm(2)), respectively. Furthermore, we show that a small-signal gain of 19.7 +/- 2.3 dB is achievable in a 1.2-mm-long waveguide. (c) 2008 American Institute of Physics.