Two-photon-induced polymerization in a laser gain medium for optical microstructure

Shiyosyi Yokoyama, Tatsuo Nakahama, Hideki Miki, and Shinro Mashiko
We have fabricated a polymer solid-state microcavity in the laser gain media by two-photon-induced polymerization technique. The photopolymerization resin contains conventional laser-dye and dendrimer. A dendrimer can encapsulate the laser-dyes, limiting cluster formation and intermolecular energy transfer, and promising a high level of optical gain. The effect can be extended to prepare an optically active microstructure using the two-photon-induced polymerization technique. We fabricated a polymeric microcavity, which consisted of <400 nm-linewidth strips arrange in layer-by layer structure. The periodic variation in the refractive index gave rise to Bragg reflection. A laser emission was measured in the microcavity under optical excitation. The spectral linewidth was about 0.1 nm above the lasing threshold. The laser emission is attributed both to the distributed Bragg reflection and to the high gain of a polymer medium containing laser-dye with a high concentration.