Interferometric system with deep learning algorithm to process two interferograms

An interferometric system for measuring surface characteristics of an object, the interferometric system comprising:

• a collimator positioned to receive light from a first light source having a first wavelength or a first range of wavelengths, and from a second light source having light with a smaller coherence length than light from the first light source and having a second wavelength or a second range of wavelengths different from the first wavelength or first range of wavelengths, the interferometric system configured to selectively allow light from one of the light sources to reach the collimator at a given time;
• a beamsplitter;
• a Mirau type microscope configuration including an objective lens, a plate with a central reflective spot and a beamsplitter plate to produce a reference beam and a test beam for illuminating the object;
• an imaging lens positioned to receive the test beam and the reference beam, wherein light from the test and reference beams upon reaching an image plane of the imaging lens form a plurality of interferograms at the image plane;
• an image processing unit comprising a processor and a memory with instructions stored thereon, wherein the instructions upon execution by the processor cause the processor to use an artificial neural network configured to receive two of the plurality of interferograms associated with the first light source to enable a measurement of a surface shape of the object and to receive another two of the plurality of interferograms associated with the second light source to enable a measurement of a surface roughness of the object;
• and
• a short pass filter positioned at one side of the beamsplitter to produce the reference beam associated with the first light source, wherein the beamsplitter plate of the Mirau type microscope configuration is a dichroic beamsplitter plate that allows light associated with the first light source to pass therethrough without substantial reflection, the dichroic beamsplitter plate allowing a first portion of the light associated with the second light source to pass therethrough and a second portion of the light associated with the second light source to be reflected therefrom.