Blu-Ray Astronomical Laser?

[Quetzal]

Just had a quick question.

I came across one of Kipkay's tutorials: building a blu-ray laser phaser.

While the "phaser" part isn't what I'm interested in, the beam's visibility seemed really good to me, and I was wondering if using a blu-ray diode for an astronomical laser pointer would be a good idea.

Thanks!

And, yes. I know the risks of pointing lasers in the sky. The good news is, I live pretty far from the nearest airport, and I don't get many planes in my sky.

 

[Eudaimonium]

Nope,

Pretty much everything in that video is a catastrophically bad idea, from hot-gluing components, completely omitting any sort of current regulation, using a 9-volt battery and $100 "host".

Also, AFAIK, the diode used was from KES-400 sled (PS3), which has a maximum output of maybe some 20mW if you're lucky.

Being in a very deep violet territory of 405 nanometers, Blu-ray lasers are very hardly visible even at very high powers - even if you had 500mW bluray laser, you'd still have to point people "There is the beam, see it?" in order for them to notice it.

100mW of green on the other hand, immediately attracts attention because it's very visible and bright for a given power (due to our eyes' color perception) and is sharper in your view because eyes have very difficult time focusing violet light.

I reccomend you go for good 50-100mW greenie, it'll serve you well for astronomy purposes.

 

[jimdt7]

For Astronomical Purposes i suggest a 532nm (green) laser
Probably around 100mW

Jim

 

[Quetzal]

Thanks for the advice!

Would it be a good idea to do that DealExtreme cheap green laser hack where you increase the output by turning the little limiter screw?

Or should I just get the parts and build it myself?

 

[ryansoh3]

Unfortunately, the answer is no as well.

Turning the screw is known as pot-modding. (the little screw contraption is a potentiometer, pot for short)

Messing around with the pot will kill the green module without any increased power benefits.

Well, okay, your laser will work for two seconds then die.

Going DIY is a good idea, but if you're not confidant, try a 30-50mW greenie at Lazerer.com. They have very good customer service and their products are guaranteed to be on spec.

Green Laser Pointer

Cheers! :beer:

 

[mojo_1234]

regarding the wavelength for astronomical use it depends what you're going to do...

--> if you would like to point at stars in front of an audience 532nm >30mW is perfect

--> to use it e.g. as a finder scope choose some low power red laser 650/660nm ~20 to 50mW

mo

 

[Quetzal]

yeah, what I was thinking of was the first one mojo mentioned, pointing it in front of an audience.

I feel like, if I don't start building myself, I'll never gain the confidence to do anything besides getting pre-made modules and plonking them in hosts.

There are SO MANY guides for building a laser out of bare parts (diode, driver, housing, etc) that I'm not sure what would be the best one for me to follow.

Could you point me in the direction of a guide that's applicable to what I'm trying to do?

Thanks

 

[Eudaimonium]

Unfortunately, regarding green lasers, buying premade modules is your only option - building your own is so complicated and time consuming it's not worth it. People who actually go those lenghts generally do it simply out of novelty, not for practical reasons of having a finished laser.

Your options are pretty much:
1) Buy premade laser
2) Buy module, heatsink and host and put it all together (which takes whole 2 minutes).