Profile: Optra, Inc. is a supplier of electro-optical products and design services for precise positioning, detection & measurement applications. Our products include metrology/motion control, risley prism, laser beam steering, laser detection and instrumentation. Our metrology/motion control includes nanogage proximity sensor, nanogrid planar encoder and nanoscale linear encoder. Our nanogage 100 is an optical triangulation proximity sensor with a signal-to-noise ratio, offering signal resolution down to 10nm. The nanogage proximity sensor has a signal capture range and a linear output range of 100µm. Our nanogrid is an XY planar encoder that measures the position of the sensor head relative to an encoder grid with resolution and repeatability up to the nanometer level. It allows both X and Y position measurements to be made at a single point, using a single laser diode sensing beam.