Green 100mW or Blue 2W

I am getting excited to build my first laser. I have chosen a Cree C6 host build and I'm about ready to order parts, however I'm not sure which diode to purchase. I would like to use the laser to point out stars, but I'd also like to burn things. I am wondering if a 2W Blue diode (M140) will travel far enough to point out stars. Thank you

-GreenBlader

It's not so much a matter of "Will it travel far enough?" as it is "Is it bright enough?". 2W of blue is plenty bright to point out stars *and* burn. However, 2W of blue is a lot of light and is definitely not eye safe- you *will* need safety glasses for burning anything. Great caution must be taken when operating such a high power laser.

My suggestion, if you want to burn things, is to get a 2W blue with safety glasses and use that for burning things. Then spend $10 and get a cheap 301 pointer or something similar for pointing at stars. The 301 pointers are usually sold as 5mW but are typically substantially over spec - usually anywhere from 50-100mW. Mine measures in at 90mW. For an extra $10 you can't go wrong.

Of course, at 50-100mW the 301 pointers aren't eye safe either so you should still be very cautious when operating it, especially indoors.

GreenBlader said:

I am getting excited to build my first laser. I have chosen a Cree C6 host build and I'm about ready to order parts, however I'm not sure which diode to purchase. I would like to use the laser to point out stars, but I'd also like to burn things. I am wondering if a 2W Blue diode (M140) will travel far enough to point out stars. Thank you

-GreenBlader

Click to expand...

The beam of a 100mW 532nm green will be as bright as a 1W blue and the dot as bright as a 2W blue + far less dangerous--so depends upon you application and desires. There are no 532nm green doides----only 520nm

You can compare brightness here Relative Laser Beam Brightness Calculator: (532nm 100mw) vs. (445nm 1000mw)

I would be willing to build a 50mW green, but I am only worried about if something like a moth were to fly into the beam at night. Would that be too dangerous without eye protection? I'm just worried for myself and others that may be with me.

GreenBlader said:

I would be willing to build a 50mW green, but I am only worried about if something like a moth were to fly into the beam at night. Would that be too dangerous without eye protection? I'm just worried for myself and others that may be with me.

Click to expand...

No it would not be too dangerous, or are you talking about the moth? Yes dangerous to the moth but not to you. I use my 82mW 520nm inside without glasses, but I wouldn't take a chance of a direct hit from it, even on the wall 10 feet or more it is uncomfortable to look at, just don't point it at a mirror or glass and you will be safe, just be careful.

Alan

Okay, I'm thinking about choosing a 50mW now.

GreenBlader said:

Okay, I'm thinking about choosing a 50mW now.

Click to expand...

What country are you in? You should add a location to your profile so it shows under your name, more people will answer your posts. Most of us buy our diodes/modules from DTR:
https://sites.google.com/site/dtrlpf/
He also sells on Amazon:
Amazon.com Seller Profile: DTR's Laser Shop
And on eBay. I suggest this if you are going to build one: https://sites.google.com/site/dtrlpf/home/diodes/pl520-520nm-laser-diode

Alan

I was planning on purchasing my diode from DTR. Location is set. Thanks