Cosmetics in the Lab

I spent the better part of an hour putting nail polish on mirror mounts yesterday.

i-a236b3beba80a6bc9aee27c2c4e4b938-sm_nail_polish.jpg

No, this isn’t a tragic misinterpretation of my students’ advice to “wear more pink.” It’s because the optical table looks like this:

i-1641f2bbcff75d8a775fb355575a9f2a-sm_laser_table.jpg

All those black things are mirror mounts like the one in the top picture, holding mirrors that are precisely positioned as part of one beam line or another. There are at least four different important paths in the picture above, and they tend to bend around a lot, and cross each other. Here’s the same picture with the beam lines roughly sketched in:

i-cef3026f13916f255bb737022911450e-sm_laser_table_beams.jpg

There’s one laser under the cardboard box at the bottom of the picture, and a second in the grey box at top. The dark purple beam is from the upper laser, and goes through an acousto-optic modeulator to shift its frequency, and then off to some laser diagnostics and locking stuff (the light blue stuff at upper right is part of that line). The bright pink beam at top goes to an optical fiber (the yellow wire-like thing running off the table to the left), and gets fed into the orange beam line, where it serves to “injection lock” the higher-power laser under the cardboard box. The bright red line is from the high-power laser, and heads over to the main experiment.

The main experimental chamber is on another table, with a similar array of optics on it, and a similarly tangled set of optical paths. Relative to a lot of labs, this is an uncluttered table, but if you don’t know what you’re looking at, it can be a little daunting to try to figure out what’s going on. One of my thesis students is about to shift over to working on this apparatus, from working on a different experiment, and I need him to be able to figure out the layout as quickly as possible.

Hence the nail polish. The mounts are black anodized aluminum, which means that ink doesn’t show up very well, and colored tape doesn’t stick very well. Enamel nail polish does stick, though, and shows up very clearly against the black mounts (you can see small spots of it on the mirror mounts in the top picture).

I asked Kate to get me a selection of colors, and she came through in a big way, thanks to the garish colors in the teeny-bopper section of the local CVS. Seven different colors (though the white and blue aren’t that easy to tell apart) provide plenty of options for identifying mirrors associated with different beam lines. I put a small dot on the top of each mount, which makes it easy to identify the different paths, or at least, the mirrors associated with the different paths.

(I wish I could say that this was an original idea, but my undergraduate thesis advisor used little dots of nail polish to distinguish between mirror mounts that belongs to his lab, and mounts stolen on loan from the teaching labs. I’m just using more colors than he did…)

Hopefully, this will make it a little easier for my current and future students to figure out what’s going on. If not, well, I can always donate the rest to first-year students with no fashion sense…

Comments

  1. #1 Kate Nepveu
    January 17, 2007

    Sorry about the white and the blue–I skipped a darker blue (and purple) because I didn’t think it would show up well enough on the black mounts, but I thought the white was bright enough to be distinct.

    Aren’t those colors hideous? I’m so perversely proud. I’d thought the selection would be limited because the red-pink-orange range would be too hard to tell apart, but no, they had distict and garishly day-glo versions of all three. (And that yellow!)

    And before anyone asks: I don’t think I’ve worn nail polish since our wedding, and even then it was the most natural-looking shade they had. Those bottles are for lab use _only_.

  2. #2 Chad Orzel
    January 17, 2007

    Aren’t those colors hideous? I’m so perversely proud. I’d thought the selection would be limited because the red-pink-orange range would be too hard to tell apart, but no, they had distict and garishly day-glo versions of all three. (And that yellow!)

    I forgot to mention that the yellow is actually called “Taxi Cab Yellow.” Truth in advertising, I guess…

  3. #3 yagwara
    January 17, 2007

    Yay! I am in math now, but in my in undergraduate physics life my favourite thing was being in the lab. I read your blog out of a mix of nostalgia and what could have been. (Probably I should have delurked last week?) I really enjoy the lab posts and photos.

    One of the most fun things for me about experimental work was the absurd little tasks you would find yourself doing to keep the equipment and coworkers happy.

    Although, by passing on the purchasing to Kate, you missed the opportunity to barge into the CVS and say, “I am a LASER SCIENTIST! I need colorful nail polish FOR MY EXPERIMENTS! HURRY! Do you have a saucier HOT PINK?”

  4. #4 Sean Carroll
    January 17, 2007

    You folks must be really good at the laser table game.

  5. #5 unistrut
    January 17, 2007

    Silver Sharpies are also handy when you need to write on things that are black. Stagehands love them because we can write things on black gaffers tape. You wouldn’t be able to mark out multiple paths with them, but they fit in your pocket more easily.

  6. #6 Chad Orzel
    January 17, 2007

    Although, by passing on the purchasing to Kate, you missed the opportunity to barge into the CVS and say, “I am a LASER SCIENTIST! I need colorful nail polish FOR MY EXPERIMENTS! HURRY! Do you have a saucier HOT PINK?”

    I would’ve, but my good lab coat was at the cleaner’s, and you don’t expect me to go out in public in this old thing, do you?

  7. #7 Bob Hawkins
    January 17, 2007

    I post-doc’d at the Naval Research Lab in Washington. There was a legendary tale told there, about a researcher who actually got the Navy to buy nail polish.

    Nail polish is standard for fixing adjustable electronics parts once their settings have been tweaked to perfection (trimpots, variable inductors and the like). Also for identifying critical parts. However, you had to supply your own because a purchase request for something like that would always be rejected.

    But one guy decided, no, this is a legitimate expense and the government should pay it. Call him Ahab. Anyway, the lengths to which he went were described in tones of wonderment. And, eventually, he succeeded, assuring him of immortality at NRL. One can only imagine the pleasure with which he dabbed the screwhead on a 10-turn pot with Navy-funded Maybelline fire-engine red.

  8. #8 Mary
    January 17, 2007

    We now use colored masking tape to trace some of the beam paths along the table. Our table is densely populated, to say the least, but we had memorized the beam paths over the last three or four years. Until a couple of weeks ago, when we decided that we had to change them all dramatically. It felt like sacrilege to move things all the way back at the beginning of the path, which had been set up by our predecessors year ago. We turned the wrong knobs and moved the wrong optics a couple of times, and so I spent a whole day doing the masking tape thing. I’ve even got it running up the periscope poles…

  9. #9 Carl Brannen
    January 17, 2007

    The problem of keeping track of lost (borrowed) tools is of such magnitude in blue collar America that it is common to expect machinists to supply their own tools. From my own experience with this, whenever I get a new set of tools the first thing I do is lightly spray paint them all while still in the case. I use auto paint as the stuff sticks really well.

    For marking on metal, good hardware stores sell paint markers in various colors, but they are intended for use on larger things than fingernails and wouldn’t be nearly so neat. Also, the fingernail stuff has to be excellent in terms of low dust created.

    By the way, your “a href” code doesn’t work very well.

  10. #10 Alison Chaiken
    January 17, 2007

    Speaking of feminine adornment and optical mounts, I’d like to stir up the physics blogosphere about this:

    http://www.edmundoptics.com/images/imagelib/UScatcover.gif

    Yes, it’s the latest cover of the Edmund Industrial Optics catalog, and it has a “red hot” babe showing her legs on the front cover! (She’s on the back cover as well.) Am I losing my perspective or is this inappropriate? I don’t see any attempt at humor here.

  11. #11 tonyl
    January 18, 2007

    Alison Chaiken: Speaking of feminine adornment and optical mounts, I’d like to stir up the physics blogosphere about this:

    http://www.edmundoptics.com/images/imagelib/UScatcover.gif

    Yes, it’s the latest cover of the Edmund Industrial Optics catalog, and it has a “red hot” babe showing her legs on the front cover! (She’s on the back cover as well.) Am I losing my perspective or is this inappropriate? I don’t see any attempt at humor here.

    That’s nothing. Every month I open up my microwave product digest and am awestruck at this ad which seems so completely out of place. It’s almost as if they took an ad rejected by someone advertising in Maxim, slapped their logo on the box in the picture, and sent it to this magazine.

  12. #12 tonyl
    January 18, 2007

    Drats! That link worked when I was previewing my post. Anyway, since that link just gets you to the front page, try this link:
    http://www.txtlinx.com/txtsys/txtimages/mpd%5CApril%5C0406218.jpg
    or look for microlab/fxr, “Need high-quality power splitters and couplers overnight?”
    Hopefully, one of those will work.

  13. #13 Alison Chaiken
    January 18, 2007

    You’re right tonyl, yours is worse! What are people thinking?

  14. #14 Tom Renbarger
    January 18, 2007

    Wow, microwave components are the new hot rods, I guess.

  15. #15 Zack Weinberg
    January 20, 2007

    I’m curious – why do the optical paths end up so convoluted?

  16. #16 Chad Orzel
    January 20, 2007

    The optical paths end up winding around a lot because there are a lot of circumstances in which it’s really helpful to have a beam hit two mirrors before going into some other element. It’s not absolutely necessary, but it makes some alignment procedures a lot easier.

    As laser tables go, this actually isn’t all that bad. I’ve seen much worse, usually because they started with a nearly-full table, and needed to cram another beam line in…