Planar organic photonic crystals fabricated by soft lithography

We employed mechanical patterning methods, including soft hot embossing and nanoimprinting lithography, to fabricate planar photonic crystal structures in organic materials, including both optically inert polymer matrices and light-emitting compounds exhibiting optical gain. The mechanical lithography processes allow a high-fidelity pattern transfer without reducing the emission yield, thus opening the way to the one-step realization of organic-based optoelectronic devices. Our demonstrators, presenting periodicities comprised between 250 and 600 nm, include solid-state distributed feedback cavities, exhibiting lasing emission at 630 nm, with a linewidth of about 1 nm and a pump threshold of 650 µJ cm−2 at room temperature. The potentiality of these techniques for the realization of two-dimensional planar photonic crystal structures is also presented and discussed.