Optical Design for Generating Bessel Beams for Micromanipulation

摘要

The central maximum of a Bessel beam offers a "non-diffracting" focal line of light that is useful in the fields of optical trapping and micromanipulation. This paper discusses the design and performance of diffractive optics for converting a Gaussian beam into a Bessel beam. The theoretical foundation of Bessel beams will be reviewed along with their optical properties. Bessel beams provide several unique characteristics such as a large depth of field and self-reconstruction. It is well known that the depth of field of a Bessel beam is larger than that of a Gaussian beam of equivalent size. However, this comes at the expense of very little power contained within the central maximum of the Bessel beam. Optical modeling and beam propagation methods are used to analyze what effect the number of rings has on the depth of field. This is an important consideration if Bessel beams are ever to be used in the fields of optical interconnects and imaging or in the area of laser processing. Where appropriate, comparisons are made between Bessel and Gaussian beams.