LS-20 High-Integrity Laser Shutters

High Integrity Laser Safety Beam Shutter

The Lasermet LS-20 Laser Safety Shutter is intended to provide a means of preventing accidental exposure to a potentially harmful laser beam.

It is intended to be used as part of a high-integrity safety system and includes a gravity-close blade as well as force-disconnect proving contacts. When the shutter is closed, the incoming laser beam is deflected onto an internal beam dump, where the energy is converted to heat and dissipated in the shutter’s aluminum casing. When the shutter is open, the laser beam passes through it without being interrupted.

SIL Rated Version

When correctly wired to a Lasermet Interlock® Control System, the ‘SIL3’ version can provide a safety Interlock® that meets Safety Integrity Level 3 to EN61508 and Performance Level ‘e’ to EN ISO 13849-1.

Control Options

The ‘Open‘ and ‘Close‘ buttons on top of the shutter case are used for standard operation. The shutter can be operated remotely using a remote switching station (LS-RS20). Alternatively, the shutter can be programmed to open as soon as power is turned on. When the power is turned off, the shutter will always close.

Connection to Beam Tube System

The LS-20 has entry and exit apertures that are 16 mm in diameter. These are threaded, and beam tubes can be supplied to fit the shutter case and enclose the laser beam

Beam Shutter for High Power Lasers

The internal beam dump has a maximum average power of 20 W. For higher powers, however, the beam dump can be easily removed by unscrewing it from the shutter case’s side. Beam tubes can be installed to direct the beam to a remote beam dump. This enables the shutter to be used for much higher powers, including multi-kilowatt lasers.

Shutter Blade Options

The shutter blade is made of stainless steel, which is suited to the majority of applications. If necessary, standard front silvered or dielectric mirrors can be factory installed on the blade. When using the remote beam dump option, this is generally recommended for average powers in excess of 20W. It is also recommended when using Q-switched lasers, which can cause minor ablation of the blade even when the average power is less than 20W.


The LS-20 shutter has an M6 female thread in the base, just below the beam centerline. A second M6 stud should be inserted into an anti-rotation slot in the base to prevent the shutter from turning or coming unscrewed. The slot accepts posts from both imperial and metric optical breadboards.

Laser Beam Power Measurement

When equipped with a mirror, the LS-20 allows for simple laser beam power measurement. The beam dump can be removed and a laser power meter detector head installed on the shutter’s side. When the shutter is closed, a power or energy reading can be obtained in this manner.

Model No.LS-20-24LS-20SIL-24
Max Average Power Using Internal Beam Dump20 W20 W
Max Average Power Using Separate Beam DumpUnlimitedUnlimited
Aperture Diameter16 mm
(0.63 in)
16 mm
(0.63 in)
Operating Voltage24 V DC24 V DC
Current Closed30 mA60 mA
Current Open250 mA500 mA
Internal Beam Dump CoolingConvectionConvection
Size (mm)98 x 65 x 37
(3.86 x 2.56 x 1.46 in)
98 x 65 x 73
(3.86 x 2.56 x 2.87 in)
Mass400 g
(0.88 lb)
800 g
(1.76 lb)
Safety Integrity Level (to EN 61508)TBASIL 3
Certified to EN ISO 13849-1
Safety of machinery – Safety-related parts of
control systems. Performance Level as shown
Lifetime5 x 105 Operations5 x 105 Operations
Extender Leads

The LS-20 shutters come with a 3 m (118.1 in) long lead that is permanently connected and terminated with a 15 pin high density D connector (male). This can be extended if necessary by using one or more 3 m leads (part number LEAD-LS20-3M).

Remote Switching Station

A remote switching station is available, which allows the shutter to be opened and closed by pressing buttons located outside of the shutter. In addition to start and stop buttons, there are LED indicators for ‘power on,’ ‘open,’ and ‘closed’. These are available in 2 types:

  • Fixed (LS-RS20) – Wall mounted with shutter socket and terminals for connecting to ICS
  • Floating (LS-RS20-FL) – With shutter socket and 3 m flying lead for plugging into a distribution box
Distribution Box for LS-20 Beam Shutters

These are wall mountable distribution boxes with terminals for connection to a Lasermet ICS Interlock® control system or other shutter power supply. Available with 1, 2 or 4 shutter connections.

Order code
1 wayICS-DB20-0/1
2 waysICS-DB20-0/2
4 waysICS-DB20-0/4
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Interlock® is a UK Registered Trade Mark of Lasermet