Beam Splitters

IntroductionBeam Splitters
The majority of beam splitter units offered by ULO Optics are of ‘polarization-insensitive’ type.
This means that, when the beam power is shared between several output beams, the state of
polarization is unaffected.
Many ordinary beam splitters fail in use because they do not incorporate the ‘polarization insensitive’
style of design.
ULO Optics offer many types of beam splitter assembly, with most of the standard types having
an optical clear aperture of about 30mm and suitable for use with a wide range of industrial CO2 lasers.
The polarization problem .. history
In the 1970’s and 1980’s many multi-output beamsplitters were designed with the optical components
at 45° to the incident beam.
These systems sometimes failed, because the reflectivies for S-polarization and P-polarization (Rs
and Rp) are noticeably different at 45° incidence, when using standard beamsplitter components.
The polarization solution
In the mid 1980’s Umicore Laser Optics calculated the incidence angle for which the difference between
Rs and Rp becomes too small to have an effect on performance … even when multiple power splits are
involved. By designing and building beamsplitter units where the beam incidence angle at the beamsplitter
component(s) is smaller than the upper useful limit, ULO Optics created the range of ‘polarization insensitive’
beamsplitter assemblies.
The power split ratio is independant of the state of polarization of the input beam, and the
polarization of e:50 power splits only, polarization insensitive beamsplitter components are
available (ULO Optics data section 3.1). Unlike the polarization-insensitive assemblies, the special
components are not recommended for high power use.

Beam Splitter table

Beamsplitter products
Technical data section 70.1x has data on semi-conventional beamsplitter units where the optical
component is inclined at 45° to the laser beam. The tilt angle of the beamsplitter is user-adjustable
with external controls.
Technical data section 70.2x gives examples of several 2-way beamsplitter units, including
switchable and orthogonal-split types.
Technical data section 70.3x is reserved for 3-way beamsplitters. Only one such unit has been made
(at the time of preparation of these data sheets) and future demand is uncertain.
Technical data section 70.4x describes switchable 4-way beamsplitter units. The large-size
assemblies are typically used in ceramics scribing/profiling installations.
Technical data section 70.90 details the optical modules that may be used to build switchable and
non-switchable beamsplitters in an indefinately large range of configurations and options.
Using these optical modules, Umicore Laser Optics can offer a speedy and economic design-and-build
service to produce the beamsplitter to suit your needs.
The most recent example of a special system:- an 8-way (2-beam input) fully switchable
integrated beamsplitter.