Ray-based simulation of the propagation of light with different degrees of coherence through complex optical systems

Abstract

We show the functional extension of a standard ray tracer to be capable of tracing light fields of different degrees of coherence through complex optical systems. The light fields are represented by spherical waves. An approximate reconstruction of the optical field is possible at arbitrary positions in an optical system under investigation. Therefore, we can calculate the intensity distribution as well as the complex degree of coherence between two points at arbitrary positions. Simulations of the coherence properties of basic optical systems, which can be described analytically, show excellent agreement with theory. Furthermore, we show simulations of the coherence properties of a two-tandem-array microlens beam homogenizer under illumination with fully and partially coherent light.

Vectorial ray-based diffraction integral

“…Douglas et al simulated the operation of an interferometer by ad hoc assumptions that allowed computability to be simplified, but this waived the exact description of diffraction [22]. Improvements were made by Riechert et al, but at the cost of sampling issues and relatively large computation times [23].…”

The Structure of Partially Coherent Fields

“…Another ray-based propagation method was introduced by Petruccelli and Alonso (2008), based on their earlier work on generalized radiometry (see Alonso, 2001;Petruccelli & Alonso, 2007, and references therein) that allows the propagation of the cross-spectral density through complex optical systems. Very recently, a third method was developed by Riechert, Dürr, Rohlfing, and Lemmer (2009) to propagate the temporal coherence function by means of rays; this method, however, does not as yet include diffraction effects. Pedersen and Stamnes (2000) introduced another method of propagation based on radiometric concepts.…”