Laser Interferometer:
The laser interoferometer measures the displacement of a moving object, typically an XY-stage. By applying Zeeman effect and heterodyne technique, very high accuracy is achievable (2x10^-8) at a resolution of 0.3 nm. Designed with leading edge technology, the 1000A system measures instantaneous position and sends out A-Quad-B pulses or 36 bit position data in 2’s complementary format. Wavelength compensation is also accomplished in real-time for both A-Quad-B and parallel data outputs.
PSD (phase sensitive detection):
The PSD based instrument applies phase sensitive detection technique to align a targeted object to a prescribed reference mark. The phase sensitive detection method, developed by Excel Precision, dramatically improves the signal-to-noise ratio. It is capable to measure relative rotation and translation between two objects, and align them to within tight tolerance.
