Pictures from The Noble Art of Optical Communications article by Carl Lodström, SM6MOM, KQ6AX, published in issues 4/2004 and 1/2005

This article is a two part article, it started in issue 4/2004. In part 1 Carl describes how he investigated optical communications using laser light modulated by a 144MHz carrier. In part 2 Carl gives some of the theory behind the choice of lenses and about diffraction

Many of the pictures from this article are only meaningful in colour, Unfortunately the magazine is only printed in black and white so the relevant pictures are available here. If you click on a thumbnail below it will display the full size picture. There are also some sound files so that you can hear what Carl achieved.

Sound file AMsound1.wav. An S5 signal of 800Hz AM tone	Sound file FM 12s. A good signal using FM modulation	Sound file FM 8s. A good signal using FM modulation	Carl's complete transmitter and receiver	Carl checking out some equipment	Laser bias T assembly
SFH217 PIN detector diode	Laser diode mount	Laser diode, focused on reference diode	View of Carl's house with laser transmitter source visible	View of the target site for Carl's laser link in the shopping mal opposite his house	Diffraction pattern of a Helium-Neon laser using a piece of CD as a diffraction grating
Light path inside a Monochromator	Diffraction of light from a laser pen	Diffraction of light from a torch	Close-up of spectrum produced by diffracted light from a torch	Diffraction spectrum from a sodium street light	Diffraction pattern of sunlight on a tail light pictured through an insect screen over Carl's window

Carl has written an interesting addendum to his article, click here to see what he has to say