Applying refractive beam shapers to improve other beam shaping techniques

Abstract

Refractive beam shapers of the field mapping type find use in various industrial, scientific and medical applications, where generation of a collimated beam of uniform intensity is required. Due to their unique features, such as: low output divergence, high transmittance and flatness of output beam profile and extended depth of field, refractive field mappers may also be successfully used in combination with beam shaping optics of other operational principles. This combining makes it possible to improve drastically the performance of these beam shaping techniques. For example, the non-uniformity of the beam profile of many lasers leads to complexity and inconvenience in various beam shaping techniques based on applying spatial light modulators (SLM). Applications include Computer Generated Holography (CGH), holographic projection processing applications, holographic lithography, optical trapping and laser illumination in confocal microscopes. With a collimated flattop beam provided by refractive field mappers these techniques become easier to use, more effective and reliable in operation. This paper will describe some design basics of refractive beam shapers of the field mapping type, with emphasis on the features important for applications with SLMs. There will be presented comparative results of applying the refractive beam shapers in systems of holographic lithography and other techniques.