Polymeric distributed feedback lasers by room-temperature nanoimprint lithography

Abstract

Room temperature nanoimprinting lithography is used to realize a distributed feedback laser by direct dry pressing of the conjugated polymer (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]). The laser device exhibits emission at 630 nm with a pump threshold of 25 mu J/cm(2) and a polarization contrast of the emitted light as large as 0.91. Therefore, room temperature nanoimprint lithography turns out to be very effective for producing stable patterns on light-emitting polymers for the one-step fabrication of nanopatterned optoelectronic devices. (c) 2006 American Institute of Physics

Electrically Tunable Organic Distributed Feedback Lasers Embedding Nonlinear Optical Molecules

“…We fi nd that the inclusion of the NLO layer does not signifi cantly alter the device threshold and lasing linewidth. [ 25 ] The emission wavelength of the electrically-contacted devices (photograph in Figure 4 c) embedding the NLO layer can be shifted continuously, during operation, up to a maximum blue-shift of 17 nm obtained applying a voltage of 100 V (Figure 4 d). This result corresponds to a tunability coeffi cient of 0.17 nm/V, almost twice the best performances reported by other electrically-driven tunability concepts.…”

“…The patterning process is entirely performed at room temperature in air, without surface physico-chemical treatments or exposures to light or particle beams as in conventional lithographic methods, thus fully preserving the emission and gain of the polymeric layer. [ 25 ] The surface topography of an imprinted organic bilayer, measured by atomic force microscopy (AFM) is shown in Figure 3 . The bilayer is composed by molecular systems with different molecular weights and viscoelastic properties, i.e.…”

Two-dimensional polymer photonic crystal band-edge lasers fabricated by nanoimprint lithography

“…24 To improve the lifetime of the lasers, a solution is to replace the dye molecules with semiconductor nanocrystals with optical gain 25 embedded in a printable polymer. 20 In summary, two-dimensional polymer photonic crystal band-edge lasers fabricated by nanoimprint lithography have been realized. Nanoimprint lithography offers a large scale patterning method at high resolution and high throughput.…”

“…18,19 Moreover, room temperature NIL has been proposed to minimize the degradation of the active media due to the otherwise higher temperatures. 20,21 Unfortunately, the former promising method does not lead to high aspect ratio features. Therefore, due to the relatively weak optical feedback, the dimension of the gratings has to be increased to obtain lasing action.…”

Thermal-nanoimprint lithography for perylenediimide-based distributed feedback laser fabrication

“…However, since the pressure that must be applied is at least one order of magnitude higher than the one used in a conventional T-NIL, and the pattern cavities in the mold cannot be completely filled during the RT process when thermoplastic materials are used, the achievable imprinting depths are generally lower (typically less than 150 nm) and the quality of the transfer is generally poorer [18]. This fabrication method has been employed to obtain DFB devices [22][23][24], but due to these problems their performance is often limited, i.e. high laser thresholds, no precise control in the emission wavelength given certain fabrication parameters, poor photostability, etc.…”