Why are most 445nm lasers >1W?

[waffailtrager101]

Hello everyone, I'm planning on building a handheld laser with the 1.8W 445nm A-Type M140 so i can burn some holes in random useless items.

I do have eye protection, here is the link to the ones I've purchased:Eaglepair OD5+ 190-540nm&800-1700nm Glasses

In my search for the "ultimate burning device" (while also keeping a budget), I noticed that most 445nm-450nm diodes have an output >1W, with the exception of some of the ~80mW OSRAM PL450B's.

Does anyone knows why most 445nm diodes are at such a high rating and what they are used for in labs and industry?

Also, does anyone know of any cool applications of a 1.8W 445mn laser besides melting my enemies? :lasergun:

Note: my enemies are pieces of scrap paper and electrical tape, not real people

 

[deadshadow]

the 445nm diodes are mostly more than 1w because the intended application when introduced was the visibility on projectors,so they had to be strong for the best visibility,year after years they got stronger and even changed into higher wavelenghts as 450,470 and now even some use green diodes at 520nm

 

[waffailtrager101]

Thank you for enlightening me deadshadow. Makes sense that they would come from projector, since I kept seeing ones for sale that had been extracted from a projector...

Silly me, can’t believe I didn’t realize the obvious

 

[BobMc]

Here's a link where you can check out some more diodes if you like to take a look. Best wishes with your project.

https://sites.google.com/site/dtrlpf/home/diodes

Ps, as to what are some more cool applications to do with the lasers?? Just don't burn the neighbors cat. :crackup:

 

[waffailtrager101]

Here's a link where you can check out some more diodes if you like to take a look. Best wishes with your project.

https://sites.google.com/site/dtrlpf/home/diodes

Ps, as to what are some more cool applications to do with the lasers?? Just don't burn the neighbors cat.

I was actually planning on buying the laser diode from DTR because I don't have a diode press yet

And don't worry, I would never harm any of my feline friends :san:

 

[CynicalBrad]

DTR really is the way to go when ordering diodes. The convenience of having the diode already pressed and that amazing wire he uses make it well worth it. And he is a great guy to deal with and ships very quickly.

Don't forget to consider lower powered diodes too. Burning is fun and all but it does wear off after a while. That and the beams specs from these diodes intended for projectors are absolute garbage compared to the lower powered single mode diodes such as the PLT5 450-B.

 

[Benm]

That's the big difference indeed - al these > 1 watt 455 diodes are multimode with pretty terrible beam specs and larger distances (it projects a line rather than a dot onto something say 100 meters away from you).

The lower power single mode ones provide a beam quality comparable to that of a typical good old red laser pointer using the diode from a dvd writer.

At lower distances the power difference is more impressive than you notice how bad the divergence in one direction is though. Good for laser shows and such.

But at really far range, say a kilometer or so, you could possible get more light per area from that 80 mW single mode than you can from a 2 watt multimode!

 

[Alaskan]

Check out my signiture for links to online divergence calculators. You can compare spot sizes at what ever distances you want to use for different mRad's to compare single and multimode laser diode divergences. Beyond a couple hundred meters, a relatively low power single mode diode at 1/20 the power can deliver more light in a smaller spot size than many MM burning diodes. The distance a single mode laser diode can overcome the spot size intensity of a much higher power MM diode at distance varies between different diodes, but after a distance of several hundred feet or meters, at the current 50-1000+ mw SM & MM diode offerings, the single mode diodes almost always win the contest for brilliance at distance within a given spot size area. The greater the distance, the more the single mode wins for a given lens diameter. You can make a high power multimode laser diode have better divergence than a single mode laser diode, if it's collimation lens is ten to twenty times larger diameter.

Edit: For an example, if using a NUBM44 7 watt output 450 nm MM diode, that lens is going to be several inches diameter to equal the divergence of a single mode diode using a common 6 mm diameter laser pointer lens. The NUBM44 has a divergence of about 11 mRad using a 6 mm lens while a single mode might give you .9 or even less than .5 mRad using the same lens, depending upon the diode.

 

[RedCowboy]

Blue laser diodes and blue light emitting diodes are commonly used to pump phosphor because of their efficiency, just like most all new lighting from parking lot lights to streetlights, even most flashlights and household lighting are now blue semiconductors pumping phosphor to make other wavelength light.

The payoff is higher efficiency and less waste heat, longer MTTF, and higher output.

 

[waffailtrager101]

Thank you CynicalBrad and Benm for the warning me about the beam specs.
For the most part, I'm planning on using this in relatively close areas (no greater than ~15m) so I'm not too worried this time around if the divergence is bad (but i will keep it in mind for the future). :thanks:

Thank you Alaskan for giving me the low-down on the divergence of the SM and MM diodes. :thanks:

Blue laser diodes and blue light emitting diodes are commonly used to pump phosphor because of their efficiency, just like most all new lighting from parking lot lights to streetlights, even most flashlights and household lighting are now blue semiconductors pumping phosphor to make other wavelength light.

The payoff is higher efficiency and less waste heat, longer MTTF, and higher output.

Thank you RedCowboy, I would have never though about them being used for that... :thanks: