Comment by JackMcMack
5 years ago
I've looked into building a "high resolution optics" version. Most parts [1] are easily sourceable, but the tube lens [2] has proven to be difficult.
It seems half inch diameter, 50mm focal length achromatic doublets are not that common; Thorlabs does seem to be the only source, and are (at least at the moment) not in stock.
[1] https://build.openflexure.org/openflexure-microscope/v6.1.5/...
[2] https://build.openflexure.org/openflexure-microscope/v6.1.5/...
Since you've done the research, I hope you don't mind me asking (I have little to none formal knowledge in optics).
I am trying to build a homemade projector, I was looking for what I think is a 'broadband' (visible light) 'non-polarizing' 50:50 beamsplitter but all the beamsplitters I found are quite expensive. Is there a 'lower quality' hobbyist-grade product range of beamsplitters that you could point me to? (Brands or distributors is also fine)
I'm certainly no expert, my knowledge is limited to what I picked up after a few nights of reading about the microscope.
Does the beamsplitter have to be non-polarizing? My understanding is that standard beamsplitters do the splitting by polarizing the incoming light.
Now that I think of it, you're probably using a standard display as your image source? That does indeed produce polarized light. In that case I would try a (common in photography) circular polarizing filter. Rotate the filter to match the display polarization, after that the light will be circularly polarized. I think you could use that in combination with a "standard" polarizing beamsplitter. Depending on the desired dimensions, there are a few available on aliexpress.
Thanks for the pointers, I had assumed non-polarized was a requirement but indeed didn't consider that display sources are themselves polarized.
Compatible 50mm achromatic doublets are not that common? That part needs a redesign...