RE-SCAN OPTICAL SYSTEMS AND METHODS

A re-scan optical system scans a light spot over a plane to form an image and includes an illumination system for directing, and optionally focusing, light providing an illumination light spot. A directing element scans the spot over and/or through the sample, de-scans sample light from the sample and scans the sample light. A detection system directs the de-scanned light along a path running from the directing element back to the directing element so that the directing element scans the sample light. A prism inverts and/or reverts the light, and/or the re-scan system comprises one or more elements to cause at least two foci of the light in said path, and/or the path is provided with a deflecting prism to deflect the light without inverting the light and/or to deflect the light without reverting the light.