Lens testing using 3D profilometer and zemax

• Main Author: Lin, Paul Canbo.
• Other Authors: Anand Krishna Asundi
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Manufacturing::Metrology
• Online Access: http://hdl.handle.net/10356/44648
• Institution: Nanyang Technological University

In response to the demand for speed and precision in production, there will always be development in production and metrology methodologies. 3D optical metrology poses opportunities as it is fast and non-destructive. 3D optical metrology uses structured light which do not work well with transparent objects like lenses. As the production of optical lens requires a high level of precision, precise methods of measuring the surface profile of the lens is essential in order to detect and correct manufacturing errors. 3D optical metrology should not be limited to be used on opaque objects and this project explores the opportunities of using 3D optical metrology instruments to measure the surface of a lens. The usage of Laser Confocal Displacement Meter, Laser Triangulation Displacement Sensor and Fizeau Interferometer were tested. The Laser Confocal Displacement Meter and the Laser Triangulation Displacement Sensor were first tested with opaque objects, then transparent objects and finally the lens. The Fizeau Interferometer, an instrument for testing optical surfaces was also used to verify the curvature. Measurement of a lens can be very prone to errors and computer software needs to be programmed and modified to capture the desired data.