1. www-g.eng.cam.ac.uk/CMMPE H.J. Coles, T.D. Wilkinson 11 Post-Doctoral Research Associates, 13 PhD Research Students Liquid crystals for displays Our research themes in the field of flat-panel liquid crystal displays encompass a range of different electro-optic effects that are suitable for applications including fast-switching, video frame-rate liquid crystal displays, and large area, low-power consumption, displays. The work programs can be categorised into the following headings: - Blue phases - Flexoelectro-optic effect - Ferroelectrics - Antiferroelectrics - Smectic A - PDLCs - Hybrid devices - Dye guest-host systems Liquid crystal lasers Chiral nematic liquid crystals have been shown to display a photonic band-gap and a periodic structure. From this, new varieties of micromolecular organic lasers are being developed, with the following properties: - Micrometer dimensions - Tunable emission wavelength - Single mode - High output power - Large coherence area - Low threshold - Self-organising into periodic structures CMMPE is developing new LC laser structures, such as arrays of re- combinable laser sources (above right), improving their performance, and using this technology to develop new applications. Research at CMMPE CMMPE was officially opened in 2003 by Lord Sainsbury of Turville. It is an 'embedded' research centre in the Centre for Advanced Photonics and Electronics (CAPE). Based in the Electrical Engineering Division on the West Cambridge Site, it is one of three parallel photonics research groups. CMMPE combines research scientists from a number of different disciplines including organic chemistry, physics and engineering. This enables fundamental research to be carried out in the design and synthesis of organic materials for the next generation of photonic and electronic applications. Our research areas include: Liquid crystal lasers 2D & 3D holographic projection Liquid crystals for displays Flexoelectro-optic effect Electrical & optical characterisation of dielectrics Liquid crystals for telecoms Optical pattern recognition Hybrid liquid crystal carbon nanotube devices Adaptive optics for ophthalmic imaging Non-linear optics Adaptive phase modulation devices CMMPE is developing new adaptive devices that dynamically manipulate of the phase of light, often using liquid crystals. Examples and applications of such devices include: - 2D & 3D computer generated holography (left - a computer generated hologram is used to display a video of a clock face). - Adaptive optics for ophthalmic imaging - Optical pattern recognition (comparators) - Hybrid liquid crystal carbon nanotube devices (right – a sparse array of vertically aligned carbon nanotubes are grown on a substrate and used to electrically address a nematic liquid crystal, generating a Gaussian electric field, and a switchable optical device, similar to an adaptive microlens array). Research at CMMPE CMMPE was officially opened in 2003 by Lord Sainsbury of Turville. It is an 'embedded' research centre in the Centre for Advanced Photonics and Electronics (CAPE). Based in the Electrical Engineering Division on the West Cambridge Site, it is one of three parallel photonics research groups. CMMPE combines research scientists from a number of different disciplines including organic chemistry, physics and engineering. This enables fundamental research to be carried out in the design and synthesis of organic materials for the next generation of photonic and electronic applications. Our research areas include: Liquid crystal lasers 2D & 3D holographic projection Liquid crystals for displays Flexoelectro-optic effect Electrical & optical characterisation of dielectrics Liquid crystals for telecoms Optical pattern recognition Hybrid liquid crystal carbon nanotube devices Adaptive optics for ophthalmic imaging Non-linear optics Adaptive phase modulation devices CMMPE is developing new adaptive devices that dynamically manipulate of the phase of light, often using liquid crystals. Examples and applications of such devices include: - 2D & 3D computer generated holography Left - a computer generated hologram is used to display a video of a clock face. - Adaptive optics for ophthalmic imaging - Optical pattern recognition (comparators) - Hybrid liquid crystal carbon nanotube devices Right – a sparse array of vertically aligned carbon nanotubes are grown on a substrate and used to electrically address a nematic liquid crystal, generating a Gaussian electric field, and a switchable optical device, similar to an adaptive microlens array. Above – (a) Chiral nematic structure, (b) deformation due to flexoelectro-optic and (c) dielectric coupling to an E field orthogonal to the helical axis. Left – Liquid crystal blue phases are self- assembled 3D cubic defect structures, with lattice periods of the order of the wavelength of visible light.