1. www-g.eng.cam.ac.uk/CMMPE H.J. Coles, T.D. Wilkinson C. Dobson, S. Findeisen-Tandel, D. Gardiner, C. Gillespie, O. Hadeler, P. Hands, Q. Malik, S. Morris, J. Schmidtke, P-L. Neo, + 11 PhD Research Students 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 Chiral nematic technology CMMPE has been developing a whole host of new devices based on chiral nematic liquid crystals. There are several different structures that can be used including the standing helix which forms a periodic refractive index or photonic bandgap. Typical applications: - Liquid crystal lasers - Liquid crystal telecoms components - Polarisation controllers 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 – Electroluminescent hybrid liquid crystal plastic display designed for Pelikon (a) Low light (EL), (b) direct sunlight (LC). Left – Liquid crystal blue phases are self- assembled 3D cubic defect structures, with lattice periods of the order of the wavelength of visible light. Liquid crystals for displays Above - chiral nematic can also be used in the uniform lying helix mode which allows devices which can perform colour switching (below) and multi-level phase modulation. Above - the helix pitch can be tuned by applied field, temperature, frequency and physical deformation to give a tuneable band gap.