Patent attributes
A three-dimensional imaging resonator and method therefor provides improved surface height measurement capability in optical measuring systems. A resonator including a surface of interest in a resonant image path is coupled to an external multi-pixel detector that detects an image of intensity of light reflected from or transmitted through the resonator. An imaging system is included in the resonator to image a region of a surface of interest on another reflector forming part of the resonator. By changing an effective cavity length of the resonator, the image is “scanned” in a direction perpendicular to the other reflector and a processing system stores information corresponding to resonance peaks to achieve a mapping of feature height above the surface of interest. The resonator effective cavity length can be changed by sweeping the illumination wavelength or by mechanically or otherwise altering the optical length of the resonator.
