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Indeed a laser pointer can be used as a canine dissuader. And assuming it's not high powered and used from a distance of at least a few meters it's likely not too harmful. This is assuming both beast and man are in motion, and, as you mentioned, it's just a quick swipe. I'm not advocating...

Excellent work! You're using a diode of known pedigree and a real power supply. Looks good. I did a similar mod a couple years ago. I modified a < $5.00 keychain pointer. I replaced the diode with a 15mW 635nm (sdl-7502) and the resistor (power supply) with an ns-102 (apc) supply. Some pics...

High powered laser not required :). Any legal (5 mW) laser pointer will do. I used a 15 mW red pointer for mine. See my post earlier in this thread. You should not need to spend more than $25-50 dollars on a weak laser pointer (< 20mw). It might help to be able to focus the beam, though this...

Looks good! What do you estimate the power to be?

Ah, OK. So how powerful are the 405nm diodes on this 100gig unit?

405nm? I see it as more violet than blue. Not a pure violet - there's enough blue mixed in to make it otherwise. At night, using my 50-100mW, the beam is grayish and the spot looks white/purple. Odd color.

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The first laser I purchased was a used He-Ne in the late 80's. I had to attach a power cord to the high voltage power supply, and I remember being terrified the first time I plugged it in. It lased however, and I had a lot of fun with this (1 mW??) laser. The color seemed like something out of a...

Just duplicated a youtube video I saw. Used my red laser pointer to project images of little bugs in a drop of pond water. Here's a picture of the projector: Shoestring, but functional. The laser is attached to a tripod head using a rubber band (15-20mW 635 nm - you don't need or want a...

Success!! Here's a picture of the new projector: The laser is attached to a tripod head using a rubber band (15-20mW 635 nm - you don't need or want a powerful laser for this). I adjusted the focus so most of the drop was hit by the laser stripe. I'm using an eyedropper. There's an alligator...

Uranium: I doubt the image you obtained is of a cell. It looks like a common interference pattern caused by a small object or pit on slide. The cell's nucleus it too small. Once you get a near diffraction limited sized spot the energy density would be so high you'd cook the cell. The Arbor...

I tried the pond scum thing with limited success. I went out and collected some brackish pond water. I put the water in empty Tobasco jars. Focused my DIY 635nm (15-20 mW - want to illuminate, not toast, the beasties) pointer down to a tiny sub mm speck where it railed the jar. After the...

Sure. That's how sound suppression technologies work, like noise-cancelling headphones. Play the 'inverse' of the noise and you've got silence. These 'active noise control' techniques have a lot of uses, such as quieting a car engine: Active noise control - Wikipedia, the free encyclopedia...

It's possible to use a laser as microscope, of sorts. Behold in the image below, a common 75 watt incandescent light bulb I've circled the 'A' in 'SYLVANIA', which will get magnified in the next image. To create the image below I slightly defocused my red laser brick (~80-100 mW). Next...

Calling light either a particle or wave is incorrect. It's neither. However, modeling light mathematically as either a particle or a wave is very useful for many things. Never confuse a model for the thing itself. Like waves in water, or sound waves, light will demonstrate the phenomenon of...

Ha! Nice find. I aced the test - scored a zero (perfect color acuity). Here's a screenshot: http://www.fractalfreak.com/wx/ColorAcuityTest.PNG Note this is on my CRT monitor, which is reasonably calibrated. I scored a 16 on my laptop using its LCD display. With the LCD slight head movements...

People over at <photonlexicon> seem happy with the diode thus far, at least for projection purposes. This would make good pointer also. One thing to keep in mind is manufacturing tolerances mean each diode will have a unique lasing frequency at spec'ed temp (25C). The spread is from 632-644nm...

Well, that's an improvement. However I think 1/2 to 1 watt of red is what the projector people are craving at this point. What's the cost on that Mitsubishi diode?

Good question. There seems to be something intrinsic to the construction of these diodes that limits single mode CW operation to generally less than 1/4 watt. Most of the red diodes out there are using AlGaInP 'recipes'. Recently GaN diode recipes have been developed - these are used to create...

Re: Testing the Microvision SHOWWX Laser Pico Projector Good review, appreciate this info. So it's a raster based device, like a CRT monitor. I seem to recall some projectors based on interference, where they'd reflect the laser beam off a reflective micro-display displaying an interference...