Our research on organic laser devices involves using a combination of liquid crystals and polymer materials to create hybrid lasers that are wavelength tuneable (Figure 4). We are interested in developing new laser sources based upon these organic materials in an attempt to create low-threshold lasers that are potentially compatible with low-cost manufacturing techniques. The research includes both fundamental studies of the emission characteristics such as coherence properties as well as the design and fabrication of new device architectures.
We are working in collaboration with the research groups of Professors Henry Snaith FRS and Moritz Reade in the Department of Physics (University of Oxford) to develop new thin-film lasers that combine the absorption and emission properties of perovskite structures with the feedback and reflection properties of chiral liquid crystalline materials. The aim of this work is to develop new, low threshold laser sources that are photostable and can be tuned using external stimuli. We have recently developed an amplified spontaneous emission source based upon a thin layer of perovskite material sandwiched between a chiral nematic (cholesteric) liquid crystal reflector and a gold layer (see publication below). Further work on combining the perovskites with tuneable liquid crystalline polymer reflectors for laser devices is currently in progress. This work was also carried out in collaboration with Professor Albert Schenning's group at the Eindhoven University of Technology and the Optoelectronics Research Group in the Cavendish Laboratory at the University of Cambridge.
Figure 6. ASE from a perovskite structure using a chiral nematic (cholesteric) reflector and a gold reflector.
Emission on flexible chiral nematic liquid crystal substrates.
Figure 7. ASE from a perovskite structure using a flexible chiral nematic (cholesteric) reflector.
Distributed feedback structures for laser emission.
Figure 8. Illustration of a distributed feedback perovskite laser.
Figure 9. Clustomesogen structures synthesised by the team of Dr. Yann Molard (University of Rennes 1)
Figure 10. Emission characteristics of Molybdenum-based clustomesogens in chiral nematic liquid crystals.