Some days in the hologram lab are interesting! It was a tiring and frustrating day, with all the electrical outlets in one of the labs going out and bringing post-flood rebuilding to a halt (electrician coming tomorrow). So we made some holograms!
If you are familiar with holograms, they are very sensitive to vibration. But we made a hologram of a ticking watch in motion! This shouldn’t work, but it did. And the results were very interesting!
First, we made a nice reflection hologram of a watch. We pulled out the pin to stop the ticking motion, and to make sure everything was stable. The hologram was nice and bright (and the self-developing LitiHolo Hologram Film allowed us view the hologram immediately after exposure). Great highlights off the metal, and notice the second, minute, and hour hands all with nice shadows and the reflective white strips on the hands.
Now we pushed the pin on the watch back in (tick, tick, tick), and the hands were moving again along with the mechanical motion spinning in the workings of the watch. Making a hologram of the watch while moving shouldn’t work! The movement of the hands, even the ticking of the watch should create too much vibration and ruin the hologram. We were wrong!
The second hologram shows the watch and the watch face nicely. But notice the hands are black now! The hour and minute hands turned black because the moved during the holographic exposure, creating “deconstructive interference,” but other parts of the watch were stable enough to get a clear hologram. And in this hologram, the second hand DISAPPEARED! It was moving quicker, and essentially was “erased” from the hologram altogether.
Making the Hologram
This was way simple, despite the surprising results! We used the Hologram Kit along with the Reflection Hologram Upgrade Kit (you can “Reserve” yours right now as we are rebuilding from the flood, and pay the full amount near end of June when we are back online with production). We turned the laser so that the beam spread was vertical, and laid the watch flat on the Plate Holder with a white paper behind (more on this later). We used a test glass to make sure the film plate would sit nicely on the top of the watch face without any wobble.
To make the holograms, we blocked the laser light with the shutter card, put a fresh 2″x3″ Hologram Film plate sitting right on top of the watch (like the test glass), waited about 30 seconds (in case there was any settling), and then removed the shutter card to expose for 8 minutes.
This is a shot during the exposure! Look at those lines forming on the white paper! Those are actual movement lines showing the paper moving by a few hundred nanometers (1/2 the wavelength of the exposure light)! Because the LitiHolo Hologram Film develops in real time during the exposure, at some point there is interference between the real light reflecting off the objects and the new hologram image that is forming at the same time. If there is any relative movement between the real object wavefront and the captured hologram wavefront, you can see bands that show the interference between the two.
Maybe we’ll do more on the Non-Destructive Testing capabilities of holograms, particularly with the real-time developing of the LitiHolo Film. In the mean time, take a look at “Reserving” your kits or film now for $1 (again, we hope to be back in production near the end of June, and we’ll bill your full payment then).
And you can also let us know what holograms you would like us to make in upcoming Monday – Make a Hologram blog posts (yes, it’s funny that we haven’t gotten one out on an actual Monday yet, but did I mention the electrical problems?). And if you have questions, you can leave those as well to be answered in an upcoming Hologram Hump Day – Ask a Hologram Expert post. Thanks for being part of the Hologram Community and thanks for helping us slowly get back on our feet after the office flood!
– LitiHolo