Interfermometer, Shearing, Lateral
Saturday, September 09, 2006
A Shearing Lateral Interferometer has been designed and developed that consists of four square prisms with sliding motion that provides lateral shearing and phase shifting. This allows the evaluation of the light beam’s wave front, which was collimated by the lens under test. Using immersion oil to attach the various prisms, face-to-face minimizes external mechanical vibration and atmospheric turbulence.
The four prisms are attached to each other using immersion oil. The reference prism is fixed to the base plate. Sliding one of the prisms in the “Z” direction provides lateral shearing. The amount of lateral shearing is twice the displacement. Sliding one of the prisms along the inclined surface of another prism produces phase shifts. One of the prisms is constrained to move only in the “Y” direction.
All the prism’s refractive index are a predetermined amount referenced to the lateral shearing prior to measurement. Prisms are moved in steps by a piezoelectric ceramic actuator generating a series of phase shifts. Between the actuator and the prism is a ball pivot to allow complete sliding motions (and tilt if it occurs). A set of preloaded kinematic springs guide the prisms to move only in one lateral direction.
Source: “Stable lateral-shearing interferometer for production-line inspection of lenses”, by Woo-Jong Cho and Seung-Wood Kim, Optical Engineering, March 1997; Woo-Jong Cho and Seung-Wood Kim, Korea Advanced Institute of Science and Technology, Department of Mechanical Engineering, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701, Korea
Reference: None Available
Industrial Products
posted by JD52 @ 6:10 PM,
