dichroic mirror seller or other suggestions to try and make selectable laser

[sxotty]

I have a goal to create a laser that I can swap between different wavelengths, but will still line up more or less.

I was hoping to see the difference in peaks distances when passed through a dual slit with different wavelengths. So like and RGB laser in many ways, but I am not trying to mix them. The easiest way to do it seemed to be dichroic mirrors, but I am having trouble finding nice square ones that will be easier to align except on ebay from eastern europe. I was hoping someone would sell them more locally at a reasonable price, or that someone might have a better idea about accomplishing what I wanted. Originally I was going to try and mill an aluminum disc with holes for laser modules that I could rotate to line up, but the power hookup seemed like it would be quite a hassle since they were spinning, unless I mounted batteries on the back of the disc, but that would also be a hassle to get them to select the correct module to turn on. Then I realized with RGB alone and 3 lasers I could just run the dichroic mirror and relays to turn individual laser on and off. That seemed easier. Any other suggestions would be welcomed as well as suggestions for where to pick some dichroic square mirrors in the US.

 

[aaronnoraa]

Are you a troll? Not that you'd admit to it.. just something about your language and the logic and the time consuming nature of writing a proper response. It seems that if you know what a dichroic filter is, that you would almost certainly know that there are well established ways to accomplish what you're aiming for. If by some inexplicable chance you're not a troll, I'm not trying to be an asshole, it's just the way you're writing and the ideas you're requesting an answer to (as well as the associated understanding you would need to have to ask the question in the first place, in that in learning what a dichroic filter is that you would have learned your answer in the process) seem exactly like the sort of time consuming answer that a bottom shelf piece of shit troll would set people up to write.

 

[sxotty]

That is such a weird response that itself took time. I always thought trolls spent time writing inflammatory things, but I am no expert.

Answering where a good source of dichroic filters in the US takes a few seconds if someone knows.

Suggesting better designs to accomplish the goal certainly takes a lot longer. I was hoping there might be some easy optical thing like the opposite of a retroreflector that would help align the beams, but given how a retroreflector works that seems like wishful thinking.

 

[kecked]

Omega filter surplus. Look for low pass filters

 

[sxotty]

Thanks for the suggestion and help. They only list long pass, but they also have dichroic.
I would link to them, but i am not allowed until 20 posts

I haven't found surplus on their site but I will contact them. The prices listed make me think that the slow boat from China or eastern Europe may be my choice in the end though.

 

[aaronnoraa]

That is such a weird response that itself took time. I always thought trolls spent time writing inflammatory things, but I am no expert.

Answering where a good source of dichroic filters in the US takes a few seconds if someone knows.

Suggesting better designs to accomplish the goal certainly takes a lot longer. I was hoping there might be some easy optical thing like the opposite of a retroreflector that would help align the beams, but given how a retroreflector works that seems like wishful thinking.

Sorry man, there's been a lot of trolls on here and seeing that you are a new member I was suspicious. I guess that's the real damage of what trolls do to us!

 

[kecked]

https://www.omegafilters.com/optical-filters/longpass
Dichroic refers to the type of material the filter is from. All you want is to reflect the laser and to pass all the others through so you do it starting with red straight in through a green reflect(longpass cutoff is above the green so it reflects but the red passes), those combined then go to the blue filter and same applies. End result is three beams that are combined in a single direction.

It is sometimes easier to use a red reflect to so you have the extra degrees of freedom lining up the beams.

You can add as many beams as you want PROVIDED there is enough filter separation to allow it.

One last trick if you have a wavelength real close and a filter will cost too much is you can add one and only one beam in via a polarizing beam cube. Trick is to align all the combined beams in one polarization and then add the other in from the other polarization which in your case likely means rotate on 90 degrees. You can do other stuff but I wont complicate it.

I'm sure someone can post a picture of this for you. It sound harder than it really is.

Remember you can pay tons for these filters. It's a matter of how much beam you are whiling to lose. Some can be found for a few dollars but leak 20%. also if you go away from the traditionally rgb wavelengths you'll pay more for the filters.