Abstract: The present invention provides for very rapid autofocusing of optical scanning systems. If a sample is sufficiently out of focus, the focal error signal used to focus a conventional half-blocked system can become saturated. Multiple steps toward the focus position then typically are required to bring the system into the operational range. To minimize this, a light adjustment system is provided to reduce the amount of light impinging on the half-blocked system when the focal error signal is at or near saturation. The half-blocked system then becomes primary controller again, and can move the system into a position generally close to the correct focal point. The light adjustment system then can be deactivated, but since the system now is much closer to focus, the half-blocked system can quickly bring the system into final focus. Alternatively, the photodetectors used to generate the focal error signal are segmented.

Abstract: A confocal scanning microscope includes a light source which provides a light beam and scanning optics which sweep the light beam across the surface of a sample. Light from the surface or interior of the sample passes through a pinhole lens which focuses the light on a pinhole for detection by an optical detector. An image of the surface may be scanned using the optical detector. An optical element is inserted in a detection arm of the confocal microscope. The optical element provides angular magnification and natural divergence to the beam from the surface of the sample.