If the angle of incidence of light on the mirror in the used optical scheme is large (AOI> 70-75 degrees), then this is called a "grazing scheme". Most often, these schemes are used for mirrors that operate in the short-wavelength spectral range (less than 100-150 nm), so that at grazing angles of incidence of radiation, the reflection coefficient of the coating can be significantly increased.
Usually, it is very important for the customer how small a spot in the image plane can be formed by the mirror (see the figure below). Even if a design is used where S' is infinity (collimated beam after reflection), this parameter allows you to estimate how good the output beam will be.
The spot size in the image plane can be affected by spherical aberrations, the precision of the mirror surface shape manufacturing, as well as diffraction limitations at the operating wavelength.
The general principle is that the closer the spot size to the diffraction limit, the more expensive the mirror is.
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What are the minimal mirror parameters do you need to know to order?You need for Your working spectral range:
A). decide on a combination of S,
S' and AOI (see the picture above,
here
pdf help guides); |
You
may send your request in any form,
but to speed up the process of preparing a quote, it is better to fill out a special "request
form".
You
may send additional data for the mirror
(mirror substrate material, type and
tolerance of mirror
surface, desirable radiuses, conic constants or ellipse coefficients
and etc.).
