English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Optical losses associated with the metallic contacts necessary for charge injection are an obstacle to the development of an electrically pumped polymer laser. We show that it may be possible to overcome these losses by demonstrating the operation of a distributed-feedback polymer laser fabricated upon a silver substrate. The device lasing threshold was ;150 times greater than that of an otherwise similar metal-free device, though similar to early polymer lasers. The device emission characteristics correlated well with the measured photonic band structure, allowing an explanation of the effect of the microstructure on device operation. © 2002 American Institute of Physics. @DOI: 10.1063/1.1496497# Semiconducting conjugated polymers are attractive gain media for optoelectronic devices due to their broad spectral emission range, good luminescence qualities, and ease of processing from solution. These properties suggest that it should be possible to construct compact electrically pumped lasers using polymer materials if the lasing threshold can be made sufficiently low. To date, however, electrically pumped operation of an organic laser has only been demonstrated for a molecular crystal using field-effect electrodes;1 all polymer-based lasers have so far been optically pumped. One reason for this is the need to include a metallic cathode in close proximity to the gain medium to inject electrons. This is a problem because the large absorption loss of metals at optical wavelengths inhibits lasing. In the drive towards developing an electri- cally driven polymeric laser, it is important to demonstrate that an optically pumped laser can operate in the presence of a metal. Previously, this has been achieved for hybrid distrib- uted Bragg reflector/metal microcavities 2 and microrings.3 Perhaps the most promising design is, however, the distrib- uted feedback ~DFB! laser.4 These are easily fabricated on a large scale using embossing techniques,5 possess a high Q and, hence, exhibit some of the lowest lasing thresholds observed.6 By corrugating the substrate in two directions, two-dimensional DFB lasing is possible, giving reduced thresholds and increased slope efficiencies.7 In this work we have fabricated a polymer DFB laser directly upon a metallic substrate, demonstrating that lasing is possible in the presence of a metal electrode in this tech- nologically important geometry. Furthermore, by measuring the photonic band structure of the device we are able to relate the spectral and spatial dependence of the photolumi-

Photonic band structure and emission characteristics of a metal-backed polymeric distributed feedback laser