GAUSSIAN SOFTWARE SOFTWARE

The divergence rays are initially located at the center of the beam waist and are asymptotic to the far-field diverging spherical wave. The waist rays are initially parallel to the base ray but displaced laterally by the beam waist semi-diameter. There are two types of secondary rays: РІР‚СљwaistРІР‚Сњ rays and РІР‚СљdivergenceРІР‚Сњ rays (see Fig. How are Gaussian beams propagated? Back in 1968, Jacques Arnaud at Bell Labs had the idea that Gaussian beams could be represented and rigorously propagated using geometric rays and he called this idea РІР‚Сљcomplex ray tracing.РІР‚Сњ 1-3 His concept was to surround the РІР‚СљbaseРІР‚Сњ ray (the central ray of the beam or, in other words, the ray that is typically traced in optical software) with a collection of secondary or РІР‚СљparabasalРІР‚Сњ rays. Consequently, if you start with a collection of Gaussian beams, you will finish with a collection of Gaussian beams after propagation through the system. What is so special about Gaussian beams and why would they be considered useful as a basis set? Remember that the Fourier transform of a Gaussian function is another Gaussian function, and so the functional form of a Gaussian beam does not change during propagation (compare this to a plane wave that becomes an Airy function if propagated to the far-field). While this sounds like a very indirect way of propagating an optical field, it is more straightforward to implement than one might think. The basic idea behind the Gaussian beam decomposition technique is to synthesize the desired optical field using a basis set of Gaussian beams, propagate these Gaussian beams through the system, and then reconstruct the optical field by coherently adding the individual Gaussian beams. This can certainly be done but not without first making a detour. It would be even more convenient if they could describe the initial optical field with a distribution of rays and do the conversion from rays to optical field at the end of the ray trace. If geometric rays are being used to properly ray trace through optical surfaces, it would certainly be convenient if the designer did not have to convert the optical field into a distribution of rays at each surface and then reverse the procedure after refraction/reflection.

This method does a much better job modeling nonparaxial surfaces. The rays are traced through the surface, and then turned back into an optical field (see Fig. Bellevue, WA), the optical field is converted into a distribution of rays at each surface.

GAUSSIAN SOFTWARE SOFTWARE

In more modern software such as CODE V (from Optical Research Associates Pasadena, CA) and ZEMAX (from Zemax Development Corp. In 1970s-era propagation software, the optical field was simply multiplied by a complex transmission function representing the optical element-a poor approximation to reality especially if the surfaces were aspheric. This technique is straightforward until the optical field encounters a lens or mirror. The classic approach is to represent the optical field by a complex array (real and imaginary data representing amplitude and phase) and to propagate this field via various types of near-field and far-field Fourier-transform-based propagators. Propagating an optical field through an arbitrary optomechanical system is, in general, a difficult computational problem, particularly if the field is clipped by limiting apertures located along the propagation path. Gaussian beam decomposition brings together elements of physical and geometric optics in a rather unexpected way, but its capabilities and limitations should be well-understood before the method is applied. Discussed in the literature since the 1940s and well-established in computational form since the mid-1980s, Gaussian beam decomposition is a powerful technique currently available in optical software packages from three mainstream commercial companies, who offer it as an alternative to the more traditional Fourier-based propagation techniques for calculating the optical field in an optical system.

Gaussian software