Manufacturer of optical position metrology equipment. Types include stage position metrology and absolute position measurement systems. Features vary depending upon model and include non-contact optical measurements, sensors, fiber optic components, scalable, heterodyne displacement interferometry and high signal to noise phase measurements. Also eliminates false counts even at zero slew rates. Suitable for optical lithography steppers and scanners, laser mask writers, mask and wafer inspection, calibration, deformable mirrors and lens positioning applications. Laser heads, interferometers and optics, measurement electronics, cables and feedthroughs also offered.