Optical Surfaces has been selected to supply two high precision mirrors to the Central Laser Facility at the renowned Rutherford Appleton Laboratories (Didcot, UK) for the Astra Gemini project
The mirrors will be critical beam focusing components that will help increase the intensity of the existing Astra laser by three orders of magnitude from 10^19Wcm-2 in a single beam to 10^22Wcm-2 on target in each of two beams.
The Astra Gemini project is funded by a CCLRC £3million grant in a development that will create the most intense laser in the world.
The new development will provide the UK with a unique dual-beam facility, delivering a total power of one petawatt (1000 million million watts).
The development will, when completed in 2007, enable scientists to create and investigate extreme conditions in a controlled way in the laboratory.
These conditions include temperatures as high as those found on the surface of the Sun and colossal magnetic fields that are found in the polar fields of neutron stars.
To make best use of this enhanced power the highest quality achievable off-axis parabolic focusing mirrors are required to maximise beam intensity while keeping the target outside the beam aperture.
Optical Surfaces says it was selected as the supplier for these mirrors due to its technical excellence, reasonable pricing and a proven record in manufacturing and testing large high precision optics for leading plasma physics groups around the world.
The first stage of the mirror fabrication will be to produce, in Zerodur, a single 460mm diameter, f0.62 on-axis parabolic parent.
From this Optical Surfaces will use its proprietary, flexible lapping technology and uniquely stabilised production environment to produce two 175mm diameter, f1.9 off-axis parabolic mirrors.
Typical specifications achieved by Optical Surfaces's highly experienced and skilled team of engineers and craftsmen include off-axis parabolic mirrors up to 600mm in diameter with surface accuracy's to lambda/20p-v depending upon off-axis angles.
With proprietary polishing techniques Optical Surfaces can, depending on the surface accuracy required, achieve the natural limit to the off-axis angle of around 25-30 degrees and surface micro-roughness on aspherics of ~1nm RMS.
