We report an analysis of the operation of a new type of laser resonator with two-dimensional distributed feedback from a photonic crystal. The gain medium consists of a 2-(4-biphenylyl)-5(4-tert-butylphenyl)-1,3,4-oxadiazole host doped with Coumarin 490 and DCM and is deposited on lithographically patterned Si/SiO2 structures. Bragg reflections caused by the grating diminish the group velocity of photons along some directions of crystallographic symmetry to zero, and the resulting feedback gives rise to laser oscillations. Dispersion relations for photons were calculated analytically and are used to interpret the laser emission spectra.

This letter describes a soft lithographic approach for fabricating low-cost, low-loss microlens arrays. An accurate negative reproduction ͑stamp͒ of an existing high-quality lens surface ͑master͒ is made by thermally curing a prepolymer to a silicone elastomer against the master. Fabricating the stamp on a rigid backing plate minimizes distortion of its surface relief. Dispensing a liquid photocurable epoxy loaded to high weight percent with functionalized silica nanoparticles into the features of relief on the mold and then curing this material with UV radiation against a quartz substrate generates a replica lens array. The physical and optical characteristics of the resulting lenses suggest that the approach will be suitable for a range of applications in micro and integrated optics.

Optically pumped laser emission has been observed from thin films of 8-hydroxyquinolinato aluminum (Alq) doped with a DCM dye deposited on a diffraction grating formed by imprinting a film of BCB with a mold. The BCB film, which is 4 μm thick, is deposited on a silicon or a flexible plastic substrate. Laser emission occurs at a wavelength near 655 nm which corresponds to the third order of the grating, which has a periodicity of ∼0.6 μm.

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