Optical sensor for high speed scanning of an object, e.g. for use in optical metrology, has a light source and a focussing objective that generates an astigmatic image on a sensor camera chip

摘要

Optical sensor has a light source (1) with at least one wavelength, a focussing objective (4) that is configured to be astigmatically imaging and a camera chip (9) placed in the beam path of the optical system. The optical system ensures that a focus figure, point or line from the object surface is imaged astigmatically on the camera chip. Also in the beam path is a lateral shear generating optical beam splitter. Independent claims are also included for the following:- (a) a method for imaging a narrow focal line in object space and; (b) a method for imaging a focal point in object space.