THE OPTIMIZATION OF 3-MIRROR ILLUMINATING SYSTEM FOR THE 4-BEAM MOIREINTERFEROMETER

The three-mirror illuminating system for moire interferometry consists of a Lloyds mirror and two additional mirrors at right angles to each other. This arrangement makes possible the design of a four-beam moir e interferometer system for a cross-lined specimen grating, to determi ne the u and v displacement components of the object under test. The d esign problems, including optimization of dimensions of the optical el ements and adjustment by a user, are discussed and analytically solved . The analysis was verified by the construction and laboratory use of the interferometer.