larh - 17-9-2023 at 01:09
Hi everyone! New here, came upon this forum when was looking fo some useful knowledge. Great to be finally here! Could someone help me with the
following question:
I'm in the middel of multiple diy projects/experiments. Some of them involve diy lasers, other optics. For those I need dichroic mirrors, bandpass
filters for different wavelegths.
I'm struggling with the way to find source/diy way to produce of bandpass filters and (or) dichroic mirrors. Ideally that'd be flexible plastic tapes
I could stick onto borosilicate or quatz glass. Or chemical coatings I could apply myself.
Was searching in google, found nothing about making it in a home lab setup.
Currently I need for example:
- 520-540nm transmit/ >=600nm reflect mirror
- 520-540nm reflect, >=600nm transmit mirror
- <=395nm transmit, else cut filter
- <=300nm transmit everything else cut filter
different combinations of transmittance/reflectance filters like 80/20, 50/50 of abovementioned wavelegths.
I need it all in different sizes and shapes, of some I don't know yet because I haven't performed the experiment yet. That's why plastic film would
work the best.
It doesn't have to be high quality, for the primary experiments I just need it to work somehow close to the desired.
Currently only option I see is to order what I want from China, but it takes a month to get it delivered here and still quite pricy to sepnd on
experiments which might eventually fail anyway.
Im located in indonesia btw(not local though), a lot of chemicals are available just to order online here without bureaucracy, so no problems with
acids and solvents and some toxic chemicals, diy coating chemical applications would work probably, but again can't find much info on implementation.
Sulaiman - 17-9-2023 at 03:09
For diy, a spectroscope type instrument may be workable?
(optics plus diffraction grating with a variable width slot (bandpass) or obstruction (band stop)
I guess that getting controlled thickness layers by vacuum sputtering or chemical deposition will be non-trivial, but I've never tried, so just
guessing.
Could be a large diversion from you main projects.
Sometimes you just have to close one eye and pay for stuff.
I hope I'm wrong.
Twospoons - 17-9-2023 at 12:53
https://www.youtube.com/watch?v=iwj78pR46zM&ab_channel=A...
Very interesting video on making Rugate filters on a silicon wafer. Might be applicable for you.
Aside from that, dichroic mirrors and optical bandpass filters are rather specialised, so finding them in everyday objects is going to be tricky.
Which just leaves places like Edmund Scientific, and Newport etc. ($$)
[Edited on 17-9-2023 by Twospoons]
larh - 10-10-2023 at 20:35
Thank you for the advices, will opt to buying them eventually. Aliexpress has some sellers which offer good choice, not sure how's quality
akmetal - 23-11-2023 at 01:10
I am building a raman spectrometer for eventually testing ultra pure nitric acid. I 95% of my optics and mounts from Edmund Optics. Every now and
then their mounts have to be modified but its rare.
I got my notch filter to get rid of the incident laser light used to excite the liquid to give up its raman spectra.
These sorts of optical filters are going to be 200-300 though. I sit down for weeks to optimize the needed optics because they are not cheap.
I just remembered......
Sulaiman - 23-11-2023 at 13:56
I have been in a dispensing optician shop where
spectacle lens blanks of desired prescription,
were cut and ground to fit chosen frames,
then various coatings could be applied (anti-glare, uv filter, scratchproof etc.)
Maybe a local optical technician would be interested to help you - if they exist.
They probably know quite accurately for their particular machine,
how to make a given thickness layer.
Just a thought