Dragon's Eye News - Lasers & Holography

Holocontroller II

nospam@example.com (Michael Harrison) — Fri, 10 Oct 2008 12:57:15 -0700

The next iteration of the HoloController is just about ready for use.

The on-board software is finally (no, really) ready to be wired up in the lab and I expect to do that tomorrow sometime.

The prototype controller is shown below with LEDs in place of connections to the relay board. I'll likely leave those in as I'm wiring the two together so that I can clearly see that both ends are working. The lit LED below is a temporary status light that shows me the software on the Arduino is running.

The resistors are all 10K pull down resistors for input from the several switches that I've got on my workbench for turning laser and shutter power on/off. The 10K pot serves as a stand-in for the light sensor that sits above the table and is used to verify that the shutter opened as expected. Two voltage regulators provide 9v and 5v for various applications. I'll be expanding their circuits soon to add diode protection and capacitor smoothing. An external board has TIP20's for controlling the 1W LED status lights out in the hallway. At the moment they just blink or are steady-on but with the Arduino I can make them fade and add sound back back to the experience with an external piezo speaker. I miss having an R2D2 in the hallway like I did with the Lego RCX controller I started out with.

I've got one digital and one analog pin open so sometime soon I expect I'll be expanding the system with more monitoring and someday with a touch screen or something similar.

The Arduino software is capable of driving the lab all by itself but since it doesn't have a UI, I still need to use the PC to provide an easy to use input interface.

I've updated the HoloController software with an Arduino driver that simply sends port commands like the K8000 driver did and otherwise still controls the lab and exposures. Soon I'll modify the PC software so the Arduino handles all the work which means the interface will move to an all-serial command set that can be more easily ported to other languages. The protocols are all written and tested now.

Woot! for Arduino!

A view of the table is available over here.

Technorati : arduino, automation, hologram, holography, lab
Del.icio.us : arduino, automation, hologram, holography, lab

Dead hologram controller

nospam@example.com (Michael Harrison) — Mon, 28 Apr 2008 06:39:31 -0700

Ugh. I went to power up the table on Saturday and discovered the main controller wouldn't come on.

At first I thought the laptop had frozen (it doesn't this every once in a blue moon) but no, it was running just fine.

Poking around under the table revealed a slightly melted fuse cover on the main controller and a fuse with no wire at all.

The recent electrical storms had apparently tried to toast the controller.

After purchasing some new fuses I found that the recent electrical storms had succeeded in frying the controller. As soon as I turn it on the fuse blows in a spectacular way. Short in the transformer? That's what I'm hoping.

Laser pointers now classed as weapons in AU

nospam@example.com (Michael Harrison) — Mon, 21 Apr 2008 05:51:01 -0700

Way to go, people.

NSW Premier Morris Iemma said today the Government would ban the most powerful laser pointers and make it a summary offence to carry any laser pointer without a lawful reason.

Sydney Morning Herald

Woot!

nospam@example.com (Michael Harrison) — Sat, 19 Apr 2008 12:55:59 -0700

I won first!

Hologram entry

nospam@example.com (Michael Harrison) — Sat, 19 Apr 2008 09:00:00 -0700

Well, here it is. Will it win?

Gettin' ready for the feis

nospam@example.com (Michael Harrison) — Fri, 18 Apr 2008 21:23:40 -0700

The Bluebonnet Feis that is.

What am I doing? Not dancing this time.

I'm entering this...

Continue reading "Gettin' ready for the feis"

Table testing Hades

nospam@example.com (Michael Harrison) — Mon, 28 Jan 2008 05:20:45 -0800

For what seems like forever now, I've been working on developing a DCG process for myself that I could use when making white-light copies of my silver masters.

After some inconsistent results I stripped the table top of all components and set up an interferometer to see how stable the table was.

Continue reading "Table testing Hades"

Holograms under a microscope

nospam@example.com (Michael Harrison) — Sat, 24 Nov 2007 23:25:21 -0800

While giving a talk about holography to a school group recently I mentioned that one could look at a hologram through a microscope and see what you'd see with the original subject.

Since I've got an Intel QX3 microscope I decided to capture a few images.

Continue reading "Holograms under a microscope"

Green living

nospam@example.com (Michael Harrison) — Wed, 17 Oct 2007 06:31:12 -0700

I've been working on a couple of holograms recently and while I don't have a lot of time for blogging at the moment, here are a few pictures.

The dancing shoes turned out really nice both in master and copy.

The next one was a quickie for Wifey and her mother.

It's a commemorative pitcher from Union Station in Ft. Worth.

VRP-M is working out pretty well so far, even the old film from Oct 2005 is coming out ok.

Using OneNote to make holograms

nospam@example.com (Michael Harrison) — Thu, 27 Sep 2007 06:19:07 -0700

OneNote has been written about ad-infinitum as a tool for note taking in meetings and classes, as a general information repository and as a collaboration tool but I'd like to introduce you to another use that I'm putting OneNote to.

Making holograms.

Or more specifically, documenting both the process I go through when creating a hologram and the results from that process in the form of notes and pictures.

As most of you will probably know, OneNote is a great repository for all sorts of information. It has allowed me to combine a number of sources into one place so that when needed, I can easily refer back to previous results when I'm making a new hologram.

Continue reading "Using OneNote to make holograms"

VRP-M Lessons Learned

nospam@example.com (Michael Harrison) — Tue, 25 Sep 2007 13:17:10 -0700

For almost two months now, I've been working to figure out the exposure and processing steps to use in order to get bright and clean transmission holograms using my Coherent 315M and VRP-M film.

After blowing through roughly 68 pieces of film (mostly 1.5x1" in size) I think I've finally nailed the process to use for transmission masters.

Continue reading "VRP-M Lessons Learned"

Experimenting with delayed development

nospam@example.com (Michael Harrison) — Thu, 13 Sep 2007 04:57:53 -0700

JohnK on the holography forum had asked if I'd experienced any problems with delayed development of VRP-M. He's been working on making holograms using a Coherent 315 and VRP-M film and was wondering VRP-M was sensitive to delays of several hours between exposure and development.

I normally develop right after exposure but did the following test to find out how VRP-M behaves.

Continue reading "Experimenting with delayed development"

Holography labcast 2

nospam@example.com (Michael Harrison) — Mon, 27 Aug 2007 12:26:13 -0700

It's time for another labcast and this time I'm experimenting with making a copy onto PFG-01 from a test "master" made using the 315M and VRP-M film.

The final test turned out pretty decent and was exposed for 12s, developed for 30s in TJ1 and bleached with EDTA.

The final image isn't as bright as I'd want if this weren't just a quick test but overall it's not bad. I may have time tomorrow morning to try another test with fresh developer but then again all my time might be spent watching the lunar eclipse.

Here's the cast. Let me know what you think.

Safelight for the computer

nospam@example.com (Michael Harrison) — Sat, 25 Aug 2007 23:02:41 -0700

If you find yourself needing to take your laptop into the lab, you can make life simpler by making a safelight cover for the screen.

I know most of you who make holograms don't carry around a tablet and those who carry around one probably don't make holograms but for others who, like me, do both, here's a way to take the computer into the lab without having to turn the screen off while film is out and about and you can save your "night" vision for what is probably a dimly lit lab.

Continue reading "Safelight for the computer"

Laser pulses turn water into ice - optics.org

nospam@example.com (Michael Harrison) — Thu, 23 Aug 2007 14:12:59 -0700

On the face of it this doesn't sound like much but the researchers hope to be able to use the results for optimize crystal growth.

Firing laser pulses into supercooled water creates ice crystals at specific locations in the liquid.
Using laser pulses to crystallise supercooled water into ice may seem counter-intuitive, but that's exactly what researchers in Germany and the UK have achieved. Because the pulses can be focused to a specific point in the liquid, the researchers believe that their technique will be valuable for future material and crystal growth studies. (Physical Review Letters 99 045701)

Laser pulses turn water into ice - optics.org