Bonus Content: How To Make A Diagram Of A Photon Bundle

In this post on Why Is Glass Transparent? I created an image of what I would describe as a photon bundle. See the figure below:

I did this because I could not find a 'free for re-use' image that did the same. I also set my image free for your use so please feel free to use it if you want.

In this post I describe how I made those nice photon squiggles so that you can do the same if you ever need to.

Excel Spreadsheets Are Your Friend

You will need a spreadsheet application. In my case I use Microsoft Excel but there are a number of good free spreadsheet applications out there that will do the job.

Step 1: To make the figure I start by creating the 'envelope' function which is a sine wave. This envelope will not be visible in the final image.

Here I just set up a column (column B) and start it at 0 and increment by a small amount in each row. The rows keep incrementing until they hit a value of 3.14 (i.e. π)

In the adjoining column I just calculate the sine of that number. Well, actually, I got a little fancier and calculated sin² of that number. It gives the envelope a more satisfying taper at each end.

Step 2: In the next step I set up the sine wave for the photon. Here I just set up another column that is simply incremented (Column E). In fact it is just identical to column B.

In column F I calculate the sine of the value in column E but I also multiply it by the value of column C which is the envelope I talked about in Step 1. This gives me the taper effect at the ends of the photon bundle as shown in the figure below.

Inside the sine calculation I also multiply the value in column E by the value in cell F1 which allows me to control the frequency of the sine. Technically I set it to "F$1" so that when I copy it down the column it always uses the value in F1.

Plot it out in a graph, delete the axes and gridlines and this is what you get:

To make a longer length photon all you have to do then is just change the value of the number in cell F1. Changing F1 to 20 gives me this:

There you go. I hoped this helped and I hoped you enjoyed reading my post.