System of beam narrowing for resolution enhancement and method therefor

摘要

A system of beam narrowing for resolution enhancement produces a narrowed beam for use in surface imaging. The system of beam narrowing for resolution enhancement uses a Fabry-Perot cavity to sharpen the intensity profile of a light source imaged through the system. The optical distance between reflective surfaces forming the Fabry-Perot cavity is tuned to select one of the surfaces as a target surface. The beam width is thereby optimized to a minimum width at the selected target surface. Multiple Fabry-Perot cavities can be cascaded by interposing one or more additional partly reflective surfaces between a first surface and a second underlying surface. The optical distances between all of the surfaces are tuned to select a target surface. The beam width is optimized at the selected target surface to produce a beam narrower than the beam produced by a single Fabry-Perot cavity.