Name for one kind of Czerny-Turner monochromator configuration?

[jbeale]

TL;DR

searching for name of single-mirror C-T monochromator configuration

Can anyone say if there is a specific name for the Czerny-Turner monochromator configuration shown below, but specifically when the two mirrors M1 and M2 extend into each other and combine forming one monolithic mirror M12 with one single radius of curvature? I thought I saw such a design years ago, and I'm revisiting an old project in which I'm actually trying to build it, but it would help to reference any existing work.

this figure is taken from www.researchgate.net/figure/Czerny-Turner-monochromator-S-1-and-S-2-entrance-and-exit-slits-respectively-G_fig3_36449863

remains of previous experiment

 

[jbeale]

Nevermind: apparently, the name I was looking for was Fastie–Ebert monochromator.

 

[Baluncore]

Welcome to PF.
Where if you can express yourself clearly, and ask the right question, you can answer it yourself.
We look forward to your next good question, and an introduction to another interesting esoteric device.

 

[SammyS]

Nevermind: apparently, the name I was looking for was Fastie–Ebert monochromator.

I'm more familiar with it being called Ebert-Fastie, or simply Ebert.

Below are three configurations I am most familiar with.

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