Optical Surfaces Ltd. will provide six motorized beam reducers for the British Science & Technology Facilities Council’s Central Laser Facility. The beam reducers will be used for CW alignment and “on shot” diagnostics, with a maximum of 1 percent transmission at 1053 and 527 nm and input energies up to 50 J. The on-shot mode requires a carefully designed “dump” to prevent the high energy beam from interacting with the transmitted output, which would result in high background noise and stray reflections. The Vulcan laser facility's Target Area West. Courtesy of the Science & Technology Facilities Council. Based on a Dall-Kircham off-axis mirror design, the beam reducers will have a number of folding mirrors between the primary and secondary. Optical Surfaces sales manager Dr. Aris Kouris said designing the devices was challenging. “The main challenges were related to dimensional constraints, maintenance of pointing accuracy and repeatability when switching between the two modes, and designing the system to be able to deal with the high power densities involved during the on-shot diagnostics mode,” Kouris said. “Selection of appropriate coatings was also a great challenge and specific coating limitations greatly dictated the final optical design.” The Central Laser Facility provides European scientists with state-of-the-art laser technology for experiments in physics, chemistry and biology. Its Vulcan facility is a high-power Nd:glass laser system capable of delivering up to 2.6 kJ of laser energy in long nanosecond pulse mode and up to 1015 W peak power in pulses as short as 500 fs. For more information, visit www.optisurf.com and www.stfc.ac.uk.