Surface characteristic determining apparatus

摘要

A wavelength selector (5) selects a wavelength of a broadband light source (4). A light director (BS1, BS2) directs light from the wavelength selector along a measurement path towards a region of a sample surface and along a reference path towards a reference surface, such that light reflected by the region of the sample surface and light reflected by the reference surface interfere to produce an interferogram. A controller (20) controls the wavelength selector to change the wavelength selected by the wavelength selector. A recorder (63) records successive images, each image representing the interferogram produced by a respective one of the wavelengths selected by the wavelength selector. A data processor (18, 180) processes the recorded images to produce at least one of a surface profile and a surface height map of at least a part of the sample surface. The reference path may be controlled to compensate for environmental effects such as vibration, thermal effects and air turbulence. The data processor may use a graphics processing unit to enable pixel data to be processed in parallel.

主权项

1. Apparatus for determining information relating to a sample surface, the apparatus comprising:
a wavelength selector to select a single wavelength of a broadband light source; a light director to direct light from the wavelength selector along a measurement path towards a region of a surface of a sample and along a reference path towards a reference surface such that light reflected by the region of the sample surface and light reflected by the reference surface interfere to produce an interferogram of the region of the surface of the sample; a controller to control the wavelength selector to change the single wavelength selected by the wavelength selector; a recorder to record successive images consisting of the surface of the sample, each of the successive images representing the interferogram produced by a respective one of each of the single wavelengths selected by the wavelength selector; a data processor configured to process the successive images of the surface of the sample recorded by the recorder to produce at least one of a surface profile and a surface height map of the region of the surface of the sample; and the wavelength selector comprises an acousto-optic tuneable filter (AOTF).