Integrated self‐aligned conjugated polymer fiber laser devices

Abstract

AbstractIn this letter we present a fully integrated self‐aligned distributed feedback (DFB) fiber laser device, which was directly imprinted in the conjugated polymer poly[2‐methoxy‐5 (2‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) on the top of optical fibers by using the soft lithographic technique of “liquid imprinting”. For this process master gratings (360 and 380 nm) for the feedback structure were fabricated via e‐beam lithography, transferred to an elastomeric stamp and used to imprint the grating into the highly luminescent conjugated polymer. Such second order gratings were photo‐pumped with a frequency doubled Nd:YAG laser, the laser emission (around 640 nm, depending on the used grating) was directly coupled into the waveguide and detected via a CCD spectrometer at the end of the fiber. The threshold of the laser devices was found to be in the range of 4.3 mJ/cm2 and exhibited a line width of approximately 2 nm. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)