Polymer laser based on active waveguide grating structures

Abstract

The active waveguide grating structures (AWGS) are demonstrated as distributed feedback (DFB) configuration for polymer lasers. The thin film of a typical light-emitting polymer poly [(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo-{2,1',3}-thiadiazole)] acts both as the gain medium and as the waveguide. The grating structures are fabricated separately on top of the polymer film through interference lithography. The continuous and high-quality waveguide layer of the gain medium enables laser emission with narrow linewidth. Theoretical analysis and experimental verification imply potentially excellent performance of the organic DFB lasers based on the AWGS configuration. This kind of AWGS configuration is of particular importance for the design of electrically pumped polymer lasers.

Pump spot size dependent lasing threshold in organic semiconductor DFB lasers fabricated via nanograting transfer

“…Furthermore, such configuration may benefit for a higher confinement of laser modes in the active material layer. Hence, the laser behavior will not be strongly perturbed by grating defects or additional modulations [21]. Due to the flexibility of the COC sheets, this approach may even be transferred to a roll-to-roll process, which allow for a high throughput laser fabrication at low production costs.…”

Nanoimprinted distributed feedback lasers comprising TiO2 thin films: Design guidelines for high performance sensing

“…Solid‐state distributed feedback (DFB) lasers utilizing dyes as active media have since their very first demonstration received significant attention for exhibiting single‐mode emission and wide tuning ranges in the visible wavelength regime. Such dye‐doped DFB lasers consist of a waveguiding thin film on a glass or polymer substrate and are typically made from low‐cost materials and, increasingly, via simple fabrication techniques such as interference lithography and nanoimprint , thereby replacing electron beam lithography and etching processes. Thin films of active materials are most commonly applied by evaporation or spin‐coating, but other methods such as ink‐jet printing or horizontal dipping have also been explored.…”

Gain- and feedback-channel matching in lasers based on radiative-waveguide gratings

“…In this paper, an active waveguide grating structure (AWGS) is employed to construct a DFB cavity, where a grating is fabricated on top of a layer of polymeric light-emitting medium. 13 Thus, the waveguide is an active material to provide gain of the radiation and the grating made of dielectric material provides feedback in combination with the waveguide. Experimental results revealed that a DFB cavity should be optimized such that: (1) The AWGS supports the surface-emitting resonance mode with the corresponding positive and negative firstorder diffraction reverse each other in propagation directions and overlap each other precisely in paths, achieving the DFB mechanisms.…”