Model ESU15 shutter is a compact unit designed for use with CO2 lasers of up to 500W power.

A rotary solenoid is used to rotate a mirror, which, in the ‘closed’ position reflects the laser beam onto
a water-cooled beam-dump. When the solenoid is actuated using the electronic power supply
provided, the mirror swings out of the beam which then passes unobstructed through the unit.
A return-spring is used to ensure that, should the power fail, the shutter will remain ‘closed’.
LED indicators are used to show ‘open,’, ‘closed’, and ‘error’ conditions (see Safety Features).
The shutter can be triggered manually or via an externally provided 5V TTL signal.

Technical specifications, optical / mechanical
Dimensions : See Figure 76.11.
Construction : Aluminium alloy, black / dove grey.
Silicon mirror type LSM2136.
Clear aperture : 19.0mm diameter.
Cooling : Water cooled, 6/4 size fittings.
Fittings, (2 off) : Retractable coupling rings, with 52.0mm dia. x 1.5mm pitch threads.
Max. CW power : 500W CW.
Operation speed : Opening time ≤100msec., closing time ≤200msec.
Beam dump : Built-in.
Solenoid : Rotary, 45° type.
LED display : Red = ‘open’, Green = ‘closed’, Amber = ‘error/fault’.

Technical specifications, electronic
Power supply : Mains, 230/240V or 110/115V AC.
Electronics package size : 220 x 125 x 95mm.
Display/controls : (1) Mains on/off switch/indicator, (2) Shutter open/closed switch.
(3) TTL (5V DC) input socket, (4) Manual/TTL control switch.

Safety Features
The optical clear aperture is mechanically limited to a size smaller that the mirror so as to avoid beam
As required by current legislation, the shutter has a manually operable lock mechanism. If the shutter
is locked ‘open’ (for initial setting-up) and a ‘close’ signal is present, the error LED will light. If the
shutter is locked ‘closed’ and an ‘open’ signal is present, the error LED will light. If the error LED
is lit, an audible buzzer/whistle will sound.
The beam dump unit is intended to be integral to to unit, and should not be removed except by a
skilled laser engineer.
NB: Removal of the beam dump could cause a laser beam to be emitted from the dump aperture.

Operational notes
The recommended power limit (500W CW) is set by reason of the limit on dumped power into the
internal beam dump. To maintain an even temperature at the beam dump of no more than
approximately 10°C above ambient, the cooling water needs to be circulated at a rate of 0.75 litres/
min. (at 500W CW power) while the shutter is ‘closed’. The angular accuracy of the rotary solenoid
is not sufficient for the ESU15 to be used as a 90° beam-switch.

Associated equipment
Model ESU15 is a direct fit to OPG piping (section 61.1), and to various lateral adjustment
accessories (section 72).
For special-purpose applications, the beam dump may be removed and replaced with a standard
retainer/connector ring set. This allows other equipment (eg: a power meter) to be affixed to the
dump port exit. This work should be undertaken by ULO Optics or by a skilled laser engineer only.
See Safety Features above.


Modular beam delivery units & equipment