Partial Coherence : From Classical Optics to Quantum Optics in Optical Microlithography

Sammanfattning

Over the past century the concept of optical coherence has evolved with the development of quantumoptics, alongside quantum mechanics. The use of lasers in microlithographic patterning is makingaccurate modeling and computation of projection systems using partial coherence increasingly im-portant in the modern semiconductor industry. This report aims to compile and compare theories ofpartial coherence, from mutual coherence functions to the density operator approach and the Lind-blad master equation. In classical optics, coherence is a measure of the correlation of intensities, andpartial coherence is viewed as a statistical degree of field correlation. Quantum optical coherence isdescribed in terms of photon statistics, with partial coherence originating from for example thermalfluctuations in the optical field or environmental decoherence. Mathematically the models are simi-lar, with the main difference being whether the field is described at a macroscopic or quantum scale.