# Scattering Data

## Introduction

Ever since the development of compact and user friendly computer-aided design (CAD) for analyzing various waveguiding structures, or photonic devices, there has been a growing need to make the methods more flexible and also more efficient than they were originally found. Pioneering works dealing with numerical methods suitable for optical circuit simulations and their complex analysis…

## Modeling of the Optical Components – Survey of Methods

There are several possibilities to describe basic photonic components numerically. We will briefly mention some fundamental properties and mainly their practical limitations of these simulation methods. When necessary, we will refer to the pertinent references. We can start with the Beam Propagation Method (BPM). The last two decades have been devoted to the extensive study as…

## Circuit Complexity Introduction

The description given above is very brief, and shows the fact that we are able to study (by means of numerical techniques) just a very limited range of various optical components. On the other hand, a more complex optical circuit can be somehow divided into smaller elements or units of single straight and curved waveguides. The…

## Huge BPM Devices (“mux/demux”)

Let us consider the well-known basic four-channel Mach-Zehnder multi/demultiplexer [5]. The circuit consists of three different Mach-Zehnder interferometers (MZI) [[1] p. 160], where each MZI has a different arm length. This multiplexer is designed to “collect” the signal of different wavelengths from 1500 nm to 1550 nm introduced from different inputs into the output named C…

## Multidirectional BPM Device

The second category is very close to the previous one. The structure on the figure below is another arrangement of the simple MZI. There are two crucial items on this example. First, the path difference is relatively big, what was designed by a circular loop instead of a primitive arc as done in the first example.…

## Devices Consisting of the Combination of BPM & Gratings (“Add/Drop”)

In this category, we shall study the devices, where a grating is present, BPM is unsuitable (see Figure 5). Of course, as it was mentioned we can use CMT, i.e. the OptiGrating product. At this point, we may recognize the final item of our new method. To analyze some advanced structures by means of several…

## Devices out of Scope of the BPM Technique (ring resonator)

The last category covers all those circuits, where analysis by means of the BPM technique alone is impossible. The representative of this group may be the ring resonator (see Figure 2) as was already mentioned in the introductory part of the paper. We may also try to reconsider some special omnidirectional devices under the circumstances…

## Scattering Data Approach

We will introduce two substantial features of our approach. To do so, let us assume an optical element that may be accurately simulated by the BPM. The typical representing device can be the four-port coupler shown on the first figure in this paper. Our aim is rather more complex and general study of the advanced…

## Implementation with OptiSystem

We are now ready to embark into the main part of the paper. Namely, we have already shown we could divide an advanced circuit into smaller parts that are suitable for the BPM analysis. We have also the S-data tool to provide the effective mathematical description of all those particular sub-elements. The last part missing…

## Solutions using OptiSystem

The concluding part of our discourse will show both the complexity and the flexibility of the presented modeling improvements. The OptiSystem schematic layout brings a new vision of the optical circuit behavior. Any advanced photonic circuit may be further studied as a set consisting of separated fundamental components. As we will also see, the use of…