Blue Lasing in Poly(Octanedioxy-Co-DMPPV) Copolymer Microcavity

Poly[octanedioxy-co-DMPPV] copolymer was synthesized to fabricate the microcavity device. The blue emitting polymers consist of strictly alternating conjugated PPV and non-conjugated alkyl group. The microcavity based on distributed Bragg reflector (DBR) and the spin-coated copolymer thin film shows promising lasing characteristics. A strong blue emission at 437.9 nm with 6.5 nm line width was due to cavity enhancement and large gain from the copolymer layer. Third harmonic of Nd:YAG laser(355 nm) was used as a pursed pump source and its energy threshold for lasing was around few microjoules per pulse. The lasing characteristics strongly depended on the microcavity structure and copolymer film processing. Q factor was calculated to be 67 and the operational lifetime of over 7x10(5) pulses was observed.