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We have fabricated a mechanically flexible conjugated polymer laser utilizing distributed feedback due to a two-dimensional photonic band structure. An ultraviolet-embossing process is used for nanopatterning a plastic substrate. On top we spin-coat a ladder-type poly(p-phenylene) as the active laser medium. Upon optical pumping, we observe a low threshold and nearly diffraction limited monomode laser emission perpendicular to the surface. Our results are explained within a Laue formulation for the feedback mechanism in the two-dimensional organic photonic crystal.

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Folding and unfolding of atomic layers has been performed at step edges of graphite using a scanning tunneling microscope. The technique consists of modulating the distance or bias voltage between the microscope tip and the sample when scanning selected areas. Calculation of the energies involved in the manipulations shows that tip-sample vibration can account for tearing and folding of graphitic layers.