Rsoft各个模块实例集合

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7

Basic Tutorials

This chapter contains several basic tutorial examples which illustrate the basic use of the

BeamPROP simulation engine. These tutorials are increasingly complex and build on concepts

established in earlier tutorials. It is important that you perform them in order, even if a particular

topic is of most interest to you. It is also recommended that users work through the basic tutorials

a cladding index of 1, a core index of 1.1, and a width of 7 µm. We will calculate the transmitted

power along 1000 µm of this waveguide.

This tutorial will introduce basic concepts about the RSoft CAD interface and the BeamPROP

simulation engine that are critical for every user to understand; it is recommended that every new

user work through this tutorial. For additional information about the RSoft CAD, please consult

the CAD manual.

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CAD Window Basics

We begin by opening up the RSoft CAD window. Windows users can do this via the Start menu

and Linux users can issue the command at a command prompt.

The CAD window, shown in Fig. 1, contains the following elements:

The top toolbars contain icons for standard file, editing, and viewing operations.

A toolbar along the left edge of the window

The left toolbar contains icons for standard CAD operations such as selection, zooming, and

adding different components. Additional icons control simulation and related aspects of the

program.

A status line at the bottom of the window

The status line provides information on the current layout mode, along with coordinate

display during drawing.

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Creating a New Circuit

To create a new circuit, click on the

icon in the top toolbar (the leftmost icon on the

top toolbar). The startup dialog appears, shown in Fig. 2, where basic information about the

circuit to be modeled is entered, including the wavelength of the light, the background refractive

index, the default index change between the background material and the structure, and the

approximate overall dimensions of the device.

For this simulation, we will use the following settings:

Sets the wavelength [µm] for the simulation.

Represents the real refractive index of the

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background material where no structure is

defined.

Represents the default difference between a

This sets the default width of a component

[µm];

if desired.

Once these settings are made, click

to continue. Note that changes can be made to these

the left CAD toolbar.

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Creating Variables via the Symbol Table

An important concept in the RSoft CAD is the Symbol Table. The Symbol Table allows the user

to create/modify both built-in and user-defined variables. These variables can be used to define

virtually any parameter within the CAD. Each symbol can be a function of any other symbol,

creating a parametric design environment.

The Symbol Table can be opened via the

icon in the CAD window. Figure 4

shows the symbol table for this design file which contains several symbols already defined that

correspond to the settings made in the startup dialog box above.

In this tutorial, we are going to create a variable which will be used to set the length of our slab

waveguide. Define a symbol , and set it equal to . To do this, click

variables start with a capital letter so that they will be easier to find in the symbol table.

Adding the Waveguide

We can now add the waveguide structure to the CAD layout window.

The CAD has several convenient ways to add a component. For this tutorial we choose the

straight waveguide component, or

, which has already been selected on the left