Help identifying optics.

SwearBear · Mar 4, 2011

Hey, everybody. I've recently went through a box of old computer parts that I've replaced through the years and thought I'd butcher some of them in hopes of finding something useful as well as clearing up some space in the box. I pulled these lenses/clear colored glass cube things from two CD-Rom and two DVD-Rom drives. I assume the bottom row are collimating lenses and the top row are filters of some sort. Can someone help me out and tell me what exactly each of those are? Thanks in advance.

Only last one is an actual cube, two are more like low sitting cubes, others are rectanles, in case it's hard to see.

anselm · Mar 4, 2011

Bottom row: collimating lenses.
Top row: likely some sort of beam combiners, they let one wavelength through while they
reflect another one. Commomly placed in a 45degree angle to something.

Shine your lazors through to find out, nothing beats direct first hand empirical data.

BShanahan14rulz · Mar 4, 2011

the cube splits beams based on polarization, probably. The coated filter looking ones will reflect based on wavelength, usually.

test by shining laser through the optic and rotating the laser while keeping it pointed at the optic.

Coherent Light · Mar 4, 2011

Where your glasses when you shine a laser through the lenses as you cannot predict if you'll get a reflection off the lens under test.

SwearBear · Mar 5, 2011

Well, I don't have any red pointers to shine through those. But When I shine green and purple lasers through them at an angle then part goes through and part gets reflected. In a couple of em reflected green dot looks much brighter than one that just goes through. The cube does have that diagonal line going through it like a splitter shold, according to pics I seen. But anyway, is there anyway I can make use of those without knowing what wavelength they're designed for? For instance that splitter/combiner is only going to work for a red laser and will be useless with a blue one?

BShanahan14rulz · Mar 7, 2011

If you think that something that is coated for blue lets more blue through than red or yellows, then you will see more red and yellows reflected, while blues get transmitted through.

If it is coated for red, chances are you will see blues being reflected.

PBS should work for most cheap greens and all diode lasers, just might work better for red.

holokidd · Jan 13, 2013

If you look closely at the cube you may see its not polished on a output side (s polarisation) and a couple of the top filter pieces are total reflective mirrors (specfic wavelength). As these guys said a test is worth its weight in gold ! and you can get a pointer at the local pet store(cat play) for a couple bucks.............

terramir · Jan 14, 2013

yes some of those cubes look like the ones I saw once upon a time in old cd-rom carriages the laser was mounted at a 90 degree angle to the disk so it reflected the laser into the lens if I look closely at those cubes I think that in many of them only one side of the cube has the colored part probably choosed to reflect red 780 nm or 650 nm laser light and let pretty much anything else through.
the wierd brown tones get me though there really close to red so they might be designed for a dirty older laser diode that actually had a broader spectrum than needed to filter it precisely down to the wave length needed. But this is just my best guess.
terramir
edit:
ps the laser was mounted at 90 degrees to where the laser needed to shine but the cubes were at a 45 degree angle.

Bionic-Badger · Jan 14, 2013

Um holokid, this thread was nearly 2-years-old at the time you replied to it. The OP probably hasn't been on the forum for a year or more. Check the date next time.

holokidd · Jan 14, 2013

Bionic-Badger said:
Um holokid, this thread was nearly 2-years-old at the time you replied to it. The OP probably hasn't been on the forum for a year or more. Check the date next time.

Uh? Ok so i should only post to new posts and not the old ones? dosent really make sense to me? But ok anway .............

Bionic-Badger · Jan 14, 2013

holokidd said:
Uh? Ok so i should only post to new posts and not the old ones? dosent really make sense to me? But ok anway .............

Well it's more that whatever you're responding to isn't relative anymore. It's like responding to someone trying to buy a Blu-ray diode for less than $200 with some link to a shop now. Things have changed, people have moved on.

If you've got something new, for example an update, related to an old thread (as in the last message is old), then make a new thread and link to the old one. That way people don't need to read through an entire old thread of irrelevant information just to see the new stuff at the very end.

terramir · Jan 14, 2013

in case of the optical cubes they are still relevant even today, I must be honest about this, prices change however I'm getting a dvd sled in a few days and a refresher in optics can't really hurt. Especially because I want to use most of those optics myself (not a laser pointer per se, more like a laser etcher, but there is a wealth of knowledge here.
bionic-badger I get your point and if this thread was ten pages long I would agree with you, but in this case the whole tread is relevant.
My
$.02
terramir

Bionic-Badger · Jan 15, 2013

A "refresher" in optics or whatever does not need someone posting some reply to some question that was asked years ago. The information in the thread hasn't changed, and you can find that information yourself by searching.

If you're confused about something, make a new thread, possibly referencing the old one. That way it's your question or statements that are the subject, not some hijacked thread from years past.

terramir · Jan 15, 2013

Hey,
I'm not the one that posted to this thread (initially after two years), all I'm saying that this particular thread is still relevant and helpful. So don't come down so hard on holokidd. you could have pm'ed him instead, it's just a social convention that is sad to say not used that much anymore (hey dude pull to side, maybe you shouldn't do this )
My $.02
terramir

Help identifying optics.

SwearBear

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anselm

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BShanahan14rulz

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Coherent Light

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SwearBear

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BShanahan14rulz

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holokidd

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terramir

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Bionic-Badger

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holokidd

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Bionic-Badger

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terramir

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Bionic-Badger

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terramir

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