Search results

How perfect of a circle do you need? There are cat toys that come with star caps that do exactly that, but the circle is usually just a ring of small dots. You could adjust the size with a focusing lens.

I've tried a DIY thing with a big heatsink, black chalkboard paint and a TEC0, connected to a multimeter, and then a lock-in amplifier, but it was too crude, and didn't give me any useable results... I have not tried this...

A Raspberry Pi IR Camera *should* work, and they are quite inexpensive... but, without knowing the wavelength of the welder, no one can guarantee anything. I'm guessing it's around 1 µm, but guessing isn't going to protect your retinas!

Sorry dat mijn Nederlands niet zo goed is. Ik was lui en dacht dat de regel tekst in het Engels de vertaling van je bericht was, dus daar reageerde ik op, wat niet juist was. Ik zie nu dat dat uw "ondertekeningsregel" is. Wat wil je met de laser doen? Als je hem bijvoorbeeld wilt gebruiken...

High powered blue lasers will always have rectangular beams. In fact, with any laser, if the power desired is higher than a small point source can handle without damage, the light source will have to be expanded, which opens up the laser cavity, making there be more output modes, which helps...

Budget?

If an extraterrestrial being exists on the other side of the galaxy, and you never communicate with it, does it even matter? The Drake equation is kind of silly to me. For one, we don't know how many different ways life could exist. We are carbon/water based, but there are an unknown number...

Ok. Well, let's start simple. Say that the two beams are focused to a point (don't ever focus a point on your LPM, though) on the same spot. Say both lasers are identical wavelength and identical power, for convenience. Shine 1W from laser 1 and 1W from laser 2. What is the optical power...

Maybe pedantic, but I disagree with the first statement. Depending on the light absorbed by the object, some things might burn easier with a green laser and others better with a blue laser. There's still no general way to answer the question, but if the ultimate goal is to burn, for example...

I've got pretty bad floaters myself. I'd never be able to afford any sort of fancy procedure to fix it. I don't think they have anything to do with lasers, but if they use lasers to correct them, there's probably a way that lasers could cause them. I'd be skeptical, though, that just casual...

Due to destructive interference, I would not expect the output to be 2 W. It'd probably be somewhere more than 1.414 W and less than 2 W

The most certain way to test them, and this only works once, is to wear them whilst doing your experiments. If you permanently go blind, then you know 100% for sure that the glasses didn't work. There are lots of other much much safer ways to test, but no test is 100% accurate. I'd recommend...

1940 nm c mount 500 mW interesting. Maybe it could be used to detect water? Wish I knew roughly the cost.

Owning a laser is not illegal in the USA. I.e., there is no law against it. What you do with a laser; however, could be an infraction, misdemeanor, or even a felony. All of the details are highly dependent on the state, county, or city/town laws in place. For example, I am not aware of any...

Yes. It's much more than that, though. The RGB sensors in the camera work differently from the colour cones of the human eye on a fundamental level, especially when it comes to NIR light.

The left one is the 660 nm, you can tell by the way the camera picks it up (NIR excites the blue pixels just a tiny bit, whilst visible red does not, so the closer to NIR, the more pinkish the camera records it). That said, cameras do not represent subtle differences in wavelength the way the...

https://www.ftc.gov/tips-advice/business-center/guidance/business-guide-ftcs-mail-internet-or-telephone-order It's not illegal to keep the flashlight as insurance (in the USA), but, from a moral standpoint, it's a bit sleazy. The right thing to do would be to return it. If you want to refuse...

Direct diode or DPSS? There are all sorts of crazy diode-based lasers out there in the lab world with crazy spec's, like multiple watts of single-mode TEM00 output, but who has $50k to find out? Ushio has this guy: http://www.ushio-optosemi.com/documents/uos/products/UOSE_DS_HL40071MG_Rev5.pdf...

Yes. Unless there is a protection diode or a mechanical safety, reverse polarity will damage any diode or diode-driven laser.

GITD is basically fluorescence with a really long decay time. If you were showing a moving image, a good GITD material would probably make the image too smeared and blurry, but maybe a really awful, cheap, GITD material would make the image look "artsy."