Low-Threshold Conjugated Polymer Distributed Feedback Lasers on InP Substrate

We demonstrate a low threshold polymer solid state thin-film distributed feedback (DFB) laser on an InP substrate with the DFB structure. The used gain medium is conjugated polymer poly2-methoxy-5-(2-ethylhexyloxy)-1,
4-phenylenevinylene (MEH-PPV) doped polystyrene (PS) and formed by drop-coating method. The second order Bragg scattering region on the InP substrate gave rise to strong feedback, thus a lasing emission at 638.9nm with a line width of 1.2nm is realized when pumped by a 532nm frequency-doubled Nd:YAG pulsed laser. The devices show a laser threshold as low as 7nJ/pulse.