If you are installing from the downloaded version, the installation can be started by simply running the 'Setup.exe' program.
*This program has been tested and is known to work under Microsoft Windows 95 and 98. It should also work under other versions of Windows (e.g. Windows 2000/Windows Millennium Edition/NT) but has not been tested under them.
Screen Layout
Graph Box: This is where graphs are plotted.
Cable Diagram: When a simulation is run, this diagram will display the paths of the rays of light as they travel through the cable. This does not show the entire cable, just a section from the front.
Option tabs: These are where the options can be changed. There are four tabs, the first displays the information from the simulation and is where the simulation is started from. The second tab contains options relating the cable, such as the length and the number of layers in the cable. The third tab is used to change the starting angle and position of the light ray, and the fourth tab is used to change options relating to the graph and the files generated.
Minimise Button: This is used to make the window minimised (just a title in the taskbar). Click the title in the taskbar to restore the window.
Maximise Button: Click this to change the window from full screen to a window on the desktop ad vice-versa.
Exit Button: Click this to close the program. Any unsaved data will be lost when the program is closed.
When the window is maximised, but not full screen, the window can be resized by placing the cursor on the edge of the window and moving the cursor with the left mouse button held down.
Note: The window cannot be made smaller if you have your screen resolution set to 640*480 as this is the minimum size for the window.
Getting Started
On the first tab, there is a box which contains information about the simulation. These are the averages of the distance travelled by the rays, the time they took, their speeds and their velocities. If there is only one ray being simulated, these will just be the values for the single ray.
To change the number of rays being simulated, either click on the box labelled 'Number of Rays' and type in the number of rays you wish to simulate or click on the up and down arrows to the right of the box to increase or decrease the number of rays. (increasing the number of rays with all of the other options set to default and running the simulation will make no visible difference as the rays will all follow the same path)
Note: Starting the simulation with a large number of rays could take a long time. Your computer may appear to be doing nothing during this time. To minimise waiting time, it is recommended that you do not use large numbers of rays on slower computers. Reducing the length of the cable will also help to reduce the amount of time you will have to wait.
Advanced Options
Click the 'Cable' tab to access the cable options. From here, you can change the length of the cable in the same way as with the number of rays. To change the number of layers in the cable, click the up and down arrows next to the 'No. Of Layers' box. The program will allow the cable to have up to eight layers, each with a separate thickness and refractive index. These can also be changed using the arrows or by typing in a value.
The layers refer to the different layers in the cable being simulated. These are numbered from the centre of the cable, with the core of the cable being layer 1. The thickness of the layer is the distance between the top of the layer and the bottom of the layer, not the diameter or radius of the layer. The refractive indexes specified should be from the medium surrounding the cable (normally air) to the layer.
Some common refractive indexes:
| Substance | Refractive Index |
|---|---|
| Air | 1.0003 |
| Ice | 1.31 |
| Liquid Water | 1.33 |
| Benzene | 1.50 |
| Crown Glass | 1.52 |
| Diamond | 2.42 |
This tab contains options relating to the light source. By clicking in the circles, you can choose to have all of the rays starting at the same angle or to have a range of values. If range is selected, you can specify maximum and minimum values for the angle and choose whether the angles will be evenly distributed or randomly distributed within the range. The bottom box allows the light rays to be started at a distance from the centre of the cable. All angles are in degrees, and are the angles to a line parallel to the cable.
The top box in this tab is to plot graphs. Click the boxes on the right to select the values to be plotted on the x axis and y axis. After you have run the simulation, click the 'Plot' button to plot the graph.
The bottom box is to output data to a file. After running the simulation, type in the name you want the file to be called and select the directory where you want to save it. Click the circles to choose between a text file, which is in a human-readable form, or a CSV file. CSV files can be loaded into most spreadsheet programs for further analysis. When you have selected the options you want, click the 'Save' button to save the file.
Troubleshooting
Both this document and the program to which it refers are ©2001 Ben Benfold
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