Optical bench
An optical bench is a device used to hold the elements of a linear optical system . The individual optical elements such as lenses , light sources or sensors can often be moved along the optical axis for adjustment .
The simple design of the optical benches is used for the quick construction of optical systems, for school experiments and in photography. The optical bench of an astronomical telescope , on the other hand, is elaborately optimized for particularly high mechanical stability.
In contrast to an optical bench, an optical table does not have a preferred axis, but a preferred plane .
construction
As the name describes, it is a linear carrier for optical components. There are various designs for this, such as triangular profiles (with a corner at the top), flat rectangular profiles or rail systems made up of two or four parallel round or rectangular profiles. There are tabs to match these profiles (the feet of the components), which can be moved on the rails and clamped at any point and which carry the actual optical components. Such a bench fixes the optical elements both in height and in one of the horizontal coordinates, so that only one degree of freedom remains along the bench direction. A design that is still frequently found in universities and schools are benches with a Zeiß profile , the cross-section of which is an equilateral triangle in the basic form. They were published by Carl Zeiss Jena in 1912/13 and are still available.
A linear bench for structures that often have to be changed is usually erected using small tripods or feet.
When it comes to angled beam paths, for example with a refracting prism , there are joints that can be used to assemble several such linear benches. The joints are freely rotatable and lockable.
Large format cameras , in particular, are sometimes referred to as “optical bench” because the individual elements ( lens standard , film standard ) are largely displaceable and pivotable on a common carrier, precisely the “optical bench”. This carrier is mostly a stable metal profile on a tripod with slid-on, length-adjustable and clampable holders (so-called riders) for the optically effective elements.
Mounts
The actual mount (see also the astronomical mount with similar tasks), the holder for the actual optical component, i.e. lenses , mirrors , prisms , etc. , then sit on the foot of the components .
To adjust the elements, their position must be made variable. There are also mounts with the corresponding setting options, for tilting in two axes (for mirrors, see under plane mirrors ), for fine adjustment in the xy plane transverse to the beam direction (for lenses), for rotation perpendicular to the beam direction (of polarizers ), for rotation in the beam level (for prisms) or for height adjustment (of cuvettes with liquids). However, these are only the examples that occur particularly frequently; there are many other highly specialized versions.
Most of these adjustment options are operated by hand during the basic adjustment of the beam path. But some are also operated by ( servo ) motors in order to operate them frequently and / or in an automated manner.
Web link
- Interactive simulation of an optical bench (requires Java)
Individual evidence
- ↑ Reinhard Pieper: Aufbauphysik - Your relation to the method of physics teaching and its historical development in Germany. Dissertation at the University of Cologne 1981, p. 148