COMBINING

[polop]

i know this question is old hat now but is there a cheap way of combining red and green - i have seen the gb on optics but i dont have 30$ to spend are there any ther ways - or maby places to scavange these optics

 

[rkcstr]

Hate to rain on your parade, but in this hobby $30 is a small price to pay.  I've seen people mention that you can use the optics from the PS3 laser sled, but I couldn't tell you how to.  This may be a question better suited for the optics forum rather than here.

Also, as with any sort of optics, alignment is critical.  Investing in some of those GB items would probably be a worthwhile investment.  I'd say save your money up, or if you don't have a job, find one, lol.

 

[rog8811]

If you have an old rangefinder camera knocking around you can take the optics out and use the cube.......

I have had great success with this on a number of projects, the best camera for the parts is the russian Zorki 4 which I have picked up from ebay for as little as 99p (50c) plus postage.

Photo shows the whole unit in use, I now just use the cube and have the lasers at 90 Deg to each other.

Regards rog8811

 

[polop]

if all i need is one of those cubes - i think they are the same cubes found in the dvd writers/readers - coul i use one of them. i presume they reflect the red light and pass the others - right.

 

[rog8811]

use the red straight through (polarisation will no doubt be required) and the green reflecting as you can afford to loose more green.

Regards rog8811

 

[polop]

what would be the best way of polarising a beam. as i said earlier i dont have a great deal of money to play with - but mabe some polarising filter for cameras or that like

 

[polop]

is this what you guys would reccomend. this would only cost me 6£(12$) ish to make so hopefully this design works. on ebay they sell polarisers quite cheaply and i can get an old dvd burner (or any red diode system) from the dump.   just to clarify a cube from a dead dvd drive (any speed or even read only) will pass polarised red and reflect (unpolarised) green

 

[rog8811]

I am no expert on polorisation but using the blue ray through a ps3 cube it was just a case of rotating the aixiz module until I got the best throughput.
Otherwise your drawing shows exactly what you need to do.

Regards rog8811

 

[polop]

so does that mean that some (mabye all) lasers are polarised anyway (without filters etc). the way you described turning the laser to get best through put makes it sound that way

 

[rog8811]

I believe that is so, I am sure if I am wrong someone will wade in and let us know

Regards rog8811

 

[goldfingerfif]

I don't get why you would polarize a laser? What difference does it make as it goes through the cube?

 

[rog8811]

The cube is used in 2 directions, the beam goes out through the cube polorised, it bounces back from the disc unpolorised, hits the cube and is reflected to the sensor array rather than passing back to where it came from.....I think :-/

Regards rog8811

 

[CL_]

cool, i wish i could do it

 

[likewhat]

You dont need a polarizer to get that setup to work. The beam splitter is polarizing, so if you shoot an unpolarized (randomly polarized) laser into the cube you will get light that passes straight through which will be polarized horizontally and light which will come out at 90 degrees to that which will be polarized vertically.

Diode lasers and most gas lasers emit polarized light. Solid state lasers sometimes emit polarized light, but maybe not if it is powered by batteries.

If you dont mind throwing away half of your light you can just use a 50/50 or whatever/whatever beam splitter to combine 2 beams.

 

[leukoplast]

Ok, this has been bugging the hell out of me...but what the heck is 'GB' referencing to?

 

[spensa]

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