Optical Fabrication and Metrology Laboratory

Objective:

The laboratory course is instrumental in providing students with practical hands-on experience in the fabrication and measurement of optical elements. It provides the understanding of various fabrication processes involved in developing an optical element such as planoconvex, biconvex lens and optical flats. Students are asked to make the optics with the desired dimensions. Emphasis is placed on the selection and use of tooling, materials and equipment used in the step-by-step manufacturing process. The metrology laboratory focusses on practical measurement techniques for optical surfaces, components and systems while comparing the measurement results with the specifications relating to fabrication issues. Students will learn how to use instruments to measure parameters like surface roughness, curvature, and flatness.

Topics:

1. Fabrication of an optical element such as planoconvex, biconvex lens and optical flats. The process involves trepanning, grinding, roughing
2. Smoothing and deterministic polishing of optical element developed in the grinding process
3. Centering and Edging of an optical element such as biconvex lens
4. Development of beam splitter and optical mirror by optical coating
5. Quantitative testing of optical elements using polarization based Twyman-Green interferometer
6. Newton and Fizeau Interferometer for Testing of optical surface
7. Wavefront measurement by Shack Hartmann Sensor
8. Moire interferometry for radius of curvature, focal length and surface measurement, Talbot interferometry for focal length and shape measurement
9. Measurement of wedge angle of optical flat and right angle of a prism by Autocollimation