Would like more info about BiRefringent Filters (BRF)

I sometime ago read a mention of BRFs involving xrays.
I know a BRF is used to select a specific wavelength or wavelength range to narrow it down for an application to ensure a reliable frequency change of coherent light.

How are BRFs configured for a wavelength? Is it possible to determine the use case of an unknown BRF and are they attainable without spending a small fortune?
Are BRFs essentially crystals where the crystal structure is influenced by xrays during their growth that affects their structure that in turn determines their wavelength range?

I know It's a bit of a vague question but I was told there were books about matters like this written by staff from coherent a long time ago.. In a time where time is abundant I'd love to give publications and/or books like this a read!

Single,Double, or Triple plate BRF?

X-ray crystallography is used to determine the physical orientation of the birefringent crystal before and after it is cut/sawn from the boule after growth. Other then that, X-rays have nothing to do with the process.

The X-ray beam, after being projected through the crystal under test produces a pattern of diffraction spots after scattering from the crystal structure. Measuring the position and angles of the spot pattern let's you work out the 3d orientation of the crystal relative to its optical axis.

X-RAYS cannot alter the solidified crystal's structure.

Steve

Hi steve.
No idea about single double or triple plate BRF
I tried looking for more information like Sams Faq and researchgate and other then mentions of BRF there is often very little more then that.. nobody seemed to really elaborate more on BRF itself.

I guess you could say a BRF as it were to be used in an OPSL (which prompted me to learn more). How does one also identify the performance of said brf? I assume you'd put it in an optical bench and measure the behaviour of the BRF to whatever coherent light you shine through it as it should narrow/select part of your wider band IR laser light.

Is there a book or something else that provides much more info about BRF itself?

I have one of these modules on my bench.. I keep it for a lot of reasons...

This is the BRF assembly Coherent uses in Dye and Ti:saph lasers. They are cut for a given tuning range at the factory. The micrometer rotates it about its optical axis to change the tuning. It is optically lossy in transmitted polarized light except at the desired wavelength.


The more plates, the tighter the passband.
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Video of a BRF in use:

Coherent 699 / 899 Dye Laser tuning range, pumped by Verdi DPSS - YouTube

Another video:
https://youtu.be/Vp4udMmeH7M?t=171
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Site with Links:
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https://lls.nsu.ru/english/amet-bft.htm
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A typical paper is
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Birefringent filter with tilted optic axis for tuning dye lasers: theory and design by Shidong Zhu
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One catalog page:
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https://www.newlightphotonics.com/Bi...-Filter-Plates
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Steve

Super cool! Thanks for the information. For sure saving these videos and having a read!

So the BRF is the key part of determining if say an OPSL laser will lase in either orange, red or yellow?
How would they do the fragile tuning at coherent because in for example OPSL heads they have an thermal glue that dries and sets (unknown thermal glue) on a TEC so it sounds hard if not near impossible trying to tune a BRF as it requires micrometer accuracy?
I did remember from memory they had 2 small screws so maybe this is the method they use to rotate the small bracket once mounted at the correct angle to tune it.

I read somewhere that you also have to come in at a certain angle which is about 45 degrees (I believe this is called the brewster angle) to get a really low deflection and good efficiency.

How does one figure out the amount of plates on a BRF?

If you can tune the BRF to narrow down the wavelength then I assume most BRFs sourced are fairly "interchangable" between applications as long as the filter is large enough to permit full/proper conversion right? (since sourcing BRF's isnt all too easy). Kind of tempted to do a bench project like that using my OSA to learn something from it (hence my interest)
I also found this website: http://www.dmphotonics.com/Birefring...r%20Tuning.htm

(also thanks for the BRF store page.. good to see some prices listed!)

The HENE is polarized in this demo of Brewster's angle.

https://youtu.be/ApKzyZ_zKNE

Warning MATH but has demos at the end.

https://youtu.be/_D1z6t2z168

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Shaoul's Laser Videos... He uses actual lasers in his demos. I once borrowed these as a 250$ SET of video tapes when I was a kid.
~
Dr. Shaoul Ezekiel taught the man who mentored me. That man also studied under Charles Towns. (YES, That Charles Towns)
~

https://www.youtube.com/watch?v=saVE7pMhaxk
https://www.youtube.com/watch?v=urbZ8CTceu0
https://youtu.be/J4Ecq7hIzYU
https://youtu.be/_qixt0NLc9I
https://youtu.be/1cEXNLP5uE0?list=PL4E7FAAD67B171EBC
https://www.youtube.com/watch?v=aUF23ZJnN9M
https://youtu.be/RRi4dv9KgCg
https://youtu.be/jny_9JMBynU


There are more if you dig, including dye, hene, and argon lasers hands on...

Dye: Laser fundamentals III: Tunable dye laser | MIT Video Demonstrations in Lasers and Optics - YouTube

Argon:
https://youtu.be/WyMF3TNm_UU


Steve

ok this is super helpfull! Thanks Steve! I'm saving and sorting out information for myself (I keep track of what I learn overtime and categorize it for future reference like i've done in the past with projects)
I'm going to go through all this.

I tried to get the paper "Birefringent filter with tilted optic axis for tuning dye lasers: theory and design by Shidong Zhu" but sadly like a lot of research documents it was behind a paper paywall. I went through that before and tried to buy the paper but sadly it was locked behind something called an openathens account.. so assuming it's locked even for purchase to certain institutions.. Hate it's the way sometimes for ones that are eager/enthousiastic to learn

Managed to get that paper from shidong zhu you mentioned.
A lot of math but very good read! going to have to catch up on my math again.. its been a long time.

The BRF is in the OPSL to prevent wavelength drift over the wafer's tuning range of around twenty nanometers.

Steve