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The "wattage" isn't that applicable with these experiments. They want time measurements, so they want pulses as short as possible, but a lot of power in that short pulse since they get VERY few photons back. The APOLLO measurement set-up generally uses a 90 picosecond pulse with a pulse...

That's the thing, I don't think he's asking for variable monochromatic output, he's asking for a wide spectral output, like an LED. I think he's asking for an output with a FWHM of 20-30 nm, not a monochromatic output that can be adjusted by 20 to 30 nm. If it's really just monochromatic...

You would probably do better with an LED instead of a laser diode.

No problem, your English is very good overall. My picture is a an atmospheric-pressure glow discharge, similar to what you have in many ways, but also a bit different due to the different pressure regime. More specifically, it's a dielectric-barrier discharge, meaning there's a dielectric...

Yeah, I suppose you're right about a bit of sputtering. The whole time I worked on glow discharges was at atmospheric pressure, and I sometimes slip into forgetting the other things that can happen when you working at low vacuum instead of no vacuum. As far as your other question, I'm not sure...

Mmmm, plasma.... Here's the dielectric-barrier discharge system I used in my undergrad lab. It was pretty big, and when our big power supply was working, we could put a really big gap in there. I think the plates shown are like a 6-inch diameter? Oh, and this discharge pictured is at...

And see? I just proved my own point. My first time in a fantasy league ever, and I won the weekend in cold's league. Barely, but I won it. But now I have some decisions to make for next week.

That part is true, Shuji made the first blue LED at the end of 1993/beginning of 1994, and the first blue laser diode in 1995/1996, very close to 2 years later. The papers for the LED and the laser diode were published in 1994 and 1996 respectively, so I'm sure that's where they're getting the...

If it's a constant 5V driver, then the current depends on the load. Your test load may have only been pulling x amount of current at a constant 5V, but if it was truly feeding the full 5V into the diode then the current through the diode was a lot more.

Pitch is often used to refer to the spacing between elements in a regular, periodic pattern. In this case, it sounds like they're just using radial coordinates (angle/distance on an arc) instead of cartesian coordinates to specify the distance between elements in a periodic pattern of holes.

Naah, he's just a wimp. :na: Here's a REAL pilot: OtnL4KYVtDE Kai Tak Airport, Hong Kong. No longer used for jumbo jets, it was famous for the extreme approach with that final 47deg turn, at low altitude right in the middle of urban area. This 747 was what, 30deg off of the direction of...

From an earlier thread, edited for brevity. Basically, it's nonlinear optics, and it takes some real studying to get at the heart of the issue there.

It is a single emitter, ~15 microns wide. That width allows the multiple lateral mode behavior. Definitely possible to fiber couple, and as it seems you've already surmised, how difficult it is depends exactly on what kind of performance you require.

Must-read lecture from Feynman: "There's Plenty of Room at the Bottom" Feynman's Talk Read it, and keep in mind what computers look like now, and then keep in mind what computers looked like when he gave this talk, in 1959. This is what transistors looked like then (this is the first...

No word on modules this time around?

From everything I've heard, the bureaucracy and unions in California (which get a terribly bad rap in the US) ain't got NOTHING on Italy. Everything I've ever heard matches what you say (which is no surprise since you live there), that it's a terrible place to try to do any business.

ENTJ Extraverted 1 Intuitive 50 Thinking 38 Judging 56 Several *NTJ on here, so far. And like Niko, I'm barely an E. And of course, these things aren't exact and may very well miss by quite a bit, but it works as a "for fun" and simplified version of the real thing. I should...

Just one clarification, a diode only emits a single color. Red, blue, and violet laser diodes don't emit any IR light. Only IR diodes emit IR light. Green modules produce green light by starting with an IR, so the IR leaking out of green lasers is just that, leakage coming from the IR diode...

Yep. Frequency doubling is also referred to as second-harmonic generation, and you can also get third harmonic generation for "frequency tripling", and other special-cases of nonlinear optical behavior. Doubling and tripling are special cases of frequency summing. You can think of it as...