HIGHLY DIRECTIONAL STIMULATED-EMISSION FROM A POLYMER WAVE-GUIDE

We report on strong amplified spontaneous emission observed both in so lution and in neat films of a conjugated polymer. The emission charact eristics of a three-layer polymer waveguide are presented. The intense , highly directional, completely linear polarized output emission with a small beam divergence of 3 degrees can be observed for pumping abov e a threshold of 3 kW/cm(2). The properties of the output emission can be explained by leaky modes. These waveguides allow us to observe the efficient optical downconversion due to strong stimulated Raman scatt ering under appropriate excitation conditions. (C) 1998 American Insti tute of Physics. [S0021-8979(98)02922-3].