Tight focusing of plane waves from micro-fabricated spherical mirrors

摘要

We derive a formula for the light field of a monochromatic plane wave that istruncated and reflected by a spherical mirror. Our formula is valid even fordeep mirrors, where the aperture radius approaches the radius of curvature. Weapply this result to micro-fabricated mirrors whose size scales are in therange of tens to hundreds of wavelengths, and show that sub-wavelength spotsizes can be achieved. This opens up the possibility of scalable arrays oftightly focused optical dipole traps without the need for high-performanceoptical systems.