An optical microscope and method for detecting lens immersion in optical microscopy includes an ultrasound circuit acoustically coupled to both an objective lens and a sample slide of an optical microscope, the ultrasound circuit comprising an ultrasound transmitter and an ultrasound receiver. The optical microscope and method includes transmitting an ultrasound pulse from the ultrasound transmitter to the ultrasound receiver, determining that a transit time of the ultrasound pulse is less than a threshold time, and providing an output signal from the pulse discriminator indicating that the ultrasound pulse is less than the threshold time.

A semiconductor inspection tool may include a distance monitoring system that is configured to monitor the distance between a microscope of the semiconductor inspection tool and a semiconductor workpiece under inspection. The distance monitoring system may include a support member and a monitoring device mounted to an end of the support member. An opposing end of the support member may be coupled to the microscope, and an actuator may be used to spin the monitoring device around the microscope using the support member. The monitoring device is configured to spin around the microscope and generate images and/or a video that can be used to monitor the distance between the microscope and the surface of the semiconductor workpiece to ensure that a minimum distance between the microscope and the semiconductor workpiece is maintained.

It is disclosed a system and method for adjusting the alignment of a light sheet microscope. A beam splitter intercepts a fraction of light emitted by a slice of a sample illuminated by the light sheet. The intercepted light fraction is focused to form two bidimensional images on a photodetector, each bidimensional image being formed by rays coming from a respective portion of an exit pupil of the microscope's objective. At least two pairs of corresponding areas are identified in the two bidimensional images, and a mutual distance between corresponding areas of each pair is determined. A misalignment parameter indicative of a misalignment of the light sheet relative to a focal plane of the microscope's objective is then calculated, based on the determined mutual distances of the various pairs of corresponding areas. An adjustment command is then generated based on the misalignment parameter.