Integrated chromatic confocal sensor

Abstract

The present invention concerns a confocal chromatic device, comprising : at least one chromatic lens (13) with an extended axial chromatism; at least one broadband light source (19); at least one optical detection means (20, 21); and at least one measurement channel (24) with a planar Y-junction (18) made with a planar waveguide optics technology, and arranged for transferring light from said at least one light source (19) towards said at least one chromatic lens (13) and for transferring light reflected back through said at least one chromatic lens (13) towards said at least one optical detection means (20, 21).

Description

technical field [0001] The invention relates to a multi-channel color confocal sensor. [0002] The field of the invention is but not limited to 2D-3D detection and metrology systems. Background technique [0003] Chromatic confocal technology is a well-known technique used for three-dimensional (3D) surface mapping and thickness measurement in semiconductor or other industrial applications. [0004] The technique relies on the use of chromatic lenses with enhanced chromatic aberration, the focal length of which is highly dependent on the optical wavelength. Each wavelength of light passing through such a lens is focused at a different distance, or on a different focal plane. [0005] The colored lenses are embedded in a confocal setup where the light source and detection aperture are placed at the confocal plane of the colored lenses in order to reject out-of-focus light. When a reflective interface is placed in front of the colored lens, only light with a wavelength who...

AI Technical Summary

Problems solved by technology

[0014] - they are difficult to use for a large number of channels;

[0015] - Since its operating principle utilizes mode coupling between fiber cores, its coupling ratio is very wavelength dependent, which can introduce bias in the measurement

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