Auxiliary fibre optic focussing module for microscopy

摘要

A module (7) for measuring the focus of a microscope objective (4) consists of a carrier (8, 9, 10) placed vertically on the object table (6) of the microscope holding a piezoelectric tubular scanner (12) for the fine positioning in three directions of an optical near-field probe comprising a fibreglass tube (13) with a point aperture of less than 200 nm (13a) and a photodiode light-detector (14) at the other end. Two light emitting diodes (17a, 17b) illuminate the probe and two distance sensors (18a, 18b) determine its position. For measuring the intensity of a laser beam focussed through the objective, the glass-fibre probe is moved in three directions and detects the light picked up through the fibre in each position. A similar process can be used for measuring the detection volume or for measuring picture transmission capacity.