CTW28 – Polarization-Insensitive 50:50

Introduction
Model CTW 28 is a rugged, symmetrical 2-way beamsplitter of the polarization-insensitive type.
Designed for general-purpose 50:50 splitting of industrial power beams, model CTW 28 has a good
optical clear aperture, and a 160mm beam separation (equally spaced either side of the input axis).
CTW 28 can be used with equal efficiency for splitting either linearly, randomly, or circularly
polarized beams. Water cooling is provided, and internally distributed.
Technical specifications
Dimensions : See Fig 70.221
Weight : Approx 9 kg
Construction : Aluminium, black anodised.
Connectors : Umicore Laser Optics std free-rotating connectors
52.0mm dia x 1.5mm pitch, (female).
Water-cooling : Via 8/6 connectors. Internally distributed.
Power split : 50:50 (non-switchable), accuracy ±2% of total input power.
Optics : ZnSe beamsplitter. P/no 15.7ZPF4-50N
Cu mirrors P/no 19.7SMA10-00 (R>99.8%)
Max power : 3kw (estimated).
Max power loss : <0.6% (assumes zero beam-clipping).
Clear aperture : 34mm diameter.
Associated equipment
Model CTW 28 connects directly to OPG optical piping (data section 61). In common with many
other ULO Optics beam-delivery modules, the CTW 28 unit is intended to be supported by the
(rigidly-held) OPG pipes.
If required, and on request, Umicore Laser Optics can supply model CTW 28 with additional tapped or
clearance holes in the baseplate for alternative mounting arrangements.
Alignment is by use of LAX25 crosswire (data section 64).
Removal of the cover plate provides access for tilt adjustment of the intenal optical components.
(SAFETY NOTE: Only qualified/experienced laser engineers should attempt re-alignment of optics
in high power laser systems).
The wide beam separation allows use of intermediate size mirror blocks, such as TM25 or TM30 (data
section 62) in each output channel, without mechanical interference.
Applications notes
CTW 28 is particularly useful where a laser user wishes to replace an older twin-beam-output laser
with a more modern single-beam laser. The actual application may be one of many, such as ceramics
scribing; cutting with separate focusing heads, cigarette filter-tipping, etc..
Constuction note
CTW 28 is built using standard mirror and beamsplitter modules as described in technical data
section 70.90.

CTW28-Beam-splitter-diagram