LASER POINTER / SEMICONDUCTOR LASER HOLOGRAPHY
by Frank DeFreitas Holography Studio
Creative Holography Using
My magical journey of making
Inexpensive Laser Pointers
holograms with a $7.99 laser pointer
and inexpensive laser diodes.
The World's First Hologram Created Using Direct SOLAR POWER*. (1/31/99)
I consider myself to be somewhat of a holography archivist/historian, so with that in mind, I will venture to say that to the very best of my knowledge, above (right photo) is a photo of the world's first laser hologram, created in 1999, using SOLAR POWER direct to the laser. The laser was powered by a photovoltaic panel located just outside the studio window, pointed South at a 45-degree angle. The panel provided 3-volts @ 100mA at "full sun".
I must apologize for the poor quality photo of the hologram. This photo was taken with one of Kodak's very first digital cameras back in 1999. Due to the interest of this particular web page, I may have the hologram matted and framed, along with the solar panel, this year (2008) for the 10th anniversary of its creation in 2009, and may update the photo at that time (or just add a the new photo to the original shown here from 1999). On Jan. 6, 2008, I converted the photo to B&W to try and help in its appearance.
*Note: If you know of any hologram produced using a solar powered laser prior to Jan. 31, 1999, please write and let me know. However, it is now 2013, and this web site has been reviewed by millions of visitors for 15 years both within and outside of holography. I certainly do not wish to make claim to something that is not rightfully mine to make claim to. Any claims should have had the laser powered entirely by direct solar panel method, and the resulting 3D laser hologram made from that laser.
Overall, I'd say a "typical" single-beam hologram. Very good depth, though. So I'm assuming that the photovoltaic power did not affect the coherence length of the pointer at all. Quite a few reflections in the glass from taking the picture outside, though. Sorry.
The photovoltaic cell puts out 3volts at 100mA with full Sun. I assume that "full Sun" does not mean Pennsylvania in January, so I was hoping to have enough current to drive the pointer. Turns out, the reading on my photometer only dropped from 15 on the 2 scale (using batteries) to 13 on the 2 scale (using the photovoltaic cell). So I was quite surprised to see a nice, bright beam. I increased the exposure time to 8 seconds (compared to 6), to compensate for this slight drop in output power. More than likely, mid-summer Sun will bring this reading back up -- but even if not, it still is pretty much right on the money.
WARNING:: It's possible that a cloud passing in front of the Sun could drop the current and damage the electronics in the pointer. Although I can't see this as any different than a pointer being used with near-dead batteries. However, I will monitor this as the Sun begins to set, and see if the diode "wakes up" with the Sun tomorrow morning.
I'm looking to eventually use the photovoltaic cell to trickle-charge rechargeable NiCad batteries -- using the batteries for exposures and using the cell to charge them back up during the day. All controlled via switches on the same circuit. For this experiment, the hologram was created entirely with the photovoltaic cells, no batteries were in the circuit. The laser pointer was completely powered by the Sun.
The above photo on the left shows the photovoltaic cell as it rests in the Sun outside the window above my studio/lab. I bought a $3.99 outdoor light fixture (the kind you put in your backyard) which can be found at just about any home center. I took the bulb assembly out, and placed the photovoltaic cell inside. I then replaced the lens cover. The cell fit perfectly in the fixture. Since the lens cover is made to spread the light from the tiny 12volt lightbulb inside, it does just the opposite from light coming in. It takes the Sunlight as it moves from different angles and focuses it to the cell. So with this lens in place, the position of the Sun is not as critical -- providing you have it oriented correctly in the first place.
The photo on the right shows the laser beam (unspread) as it is powered from the photovoltaic cell. I ran 20-gauge wire straight down into the basement and over to the table. I connected the wire directly to the laser pointer using small micro-alligator clips. It really is amazing to sit here and look over at the laser light on the table -- knowing that the power is coming from the Sun -- FREE! It was a lot of fun working this out. I'm happy that it worked, and I'm pleased with the results.
If you would like to make a solar-powered hologram of your own, I now offer Solar Powered Laser Holography workshops here in my studio. You'll make a great hologram, and also construct your own safe, low-power, solar-powered laser to take home with you.
Now it's time to get back to other planned experiments.
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Frank DeFreitas Holography