Off
Axis Parabolic (hereinafter - OAP)
mirrors is part of the surface of paraboloid
of revolution.
In grazing schemes, the Angle Of
Incidence (AOI) of radiation on the mirror is
large (60-89 degrees),
and the mirror itself is accordingly located far from the vertex of the parent
parabola (see figure below).
OAP
mirrors in grazing schemes are often used when
customer works in short spectral wavelength
range
at a large
AOI (about 60-89 degrees) with standard task
to make collimated beam from point source
(or inverse task - from collimated beam to
point).
The advantage of
OAP mirrors is complete absence of spherical aberrations and, accordingly,
the possibility of obtaining a diffraction-limited spot
(or "ideal" paralell beam) in any configuration.
The disadvantage of OAP mirrors is higher cost and longer delivery terms.
Usually, it is very important for the customer
how small a spot in the image plane can be formed by the mirror.
Even if task is inverse (i.e. - outpit ideal
collimated beam), this parameter allows you
to estimate
important data about output beam
divergence
The
spot size in the image plane for OAP mirror depends on tolerance of the mirror surface shape
manufacturing and
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.
|
What are the minimal mirror parameters do you need to know to order?You need for Your working spectral range:
A). choose Effective
Focal Length 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, tolerance of mirror
surface figure, ellipse parameters and etc.).
