Beam Blocks and Traps
- Beam Blocks and Traps for CW or Pulsed Lasers
- Solutions for up to 500 W
- Essential Component for Laser Lab Safety
Visible CW Only
Pulsed and CW
30 mm Cage System
Liquid-Cooled Beam Block,
IR Pulsed and CW
|Item #||Laser Input||Wavelength
|BT600(/M)||CW||200 nm - 3 µm||80 Wb||30 mJ/cm2||Trap|
|BT610(/M)||CW & Pulsed||400 nm - 2.5 µm||30 W||40 J/cm2 c,d|
|BT620(/M)||CW & Pulsed||1 - 12 µm||50 We||25 J/cm2 c,d|
|BTC30||CW||200 nm - 3 µm||5 Wf||30 mJ/cm2 c|
|LB2(/M)||CW & Pulsed||1 - 12 µm||80 Wg||25 J/cm2 c,d|
|LB2L(/M)||CW & Pulsed||1 - 12 µm||500 Wh||25 J/cm2 c,d||Liquid-Cooled Block|
- Laser Safety Devices Reduce Risk of Laser Damage
- Solutions for up to 500 W or 40 J/cm2 (10 Hz) Beams
- Models for Wavelengths from 200 nm - 12 µm
- Post, 30 mm Cage, or 60 mm Cage Mounting
Thorlabs' selection of Beam Traps and Beam Blocks are common laser lab safety devices. They are designed to be the terminal piece of an optical system and absorb the incident laser beam. The beam traps that feature both 4-40 taps for integration into a 30 mm cage system and an 8-32 (M4) tap for post mounting are suitable for CW (BT600) or CW and pulsed (BT610 & BT620) beams up to 80 W. The BTC30 quick-release trap is suitable for 5 W CW lasers and can be easily inserted into and removed from existing 30 mm cage systems without disassembly. The LB1(/M) visible beam block provides a large absorptive target area for CW beams up to 10 W. The LB2(/M) and LB2L(/M) IR beam blocks absorb pulsed beams up to 25 J/cm2 and are also compatible with our 60 mm cage systems. The LB2(/M) beam block absorbs CW beams up to 80 W. The LB2L(/M) IR beam block is designed to be liquid cooled, allowing it to handle a maximum average power of 500 W (CW), and has connectors for 1/4" (6 mm) inner diameter tubing.
We also offer light traps and terminators for fiber optic applications.
Laser Safety and Classification
Safe practices and proper usage of safety equipment should be taken into consideration when operating lasers. The eye is susceptible to injury, even from very low levels of laser light. Thorlabs offers a range of laser safety accessories that can be used to reduce the risk of accidents or injuries. Laser emission in the visible and near infrared spectral ranges has the greatest potential for retinal injury, as the cornea and lens are transparent to those wavelengths, and the lens can focus the laser energy onto the retina.
Safe Practices and Light Safety Accessories
- Laser safety eyewear must be worn whenever working with Class 3 or 4 lasers.
- Regardless of laser class, Thorlabs recommends the use of laser safety eyewear whenever working with laser beams with non-negligible powers, since metallic tools such as screwdrivers can accidentally redirect a beam.
- Laser goggles designed for specific wavelengths should be clearly available near laser setups to protect the wearer from unintentional laser reflections.
- Goggles are marked with the wavelength range over which protection is afforded and the minimum optical density within that range.
- Laser Safety Curtains and Laser Safety Fabric shield other parts of the lab from high energy lasers.
- Blackout Materials can prevent direct or reflected light from leaving the experimental setup area.
- Thorlabs' Enclosure Systems can be used to contain optical setups to isolate or minimize laser hazards.
- A fiber-pigtailed laser should always be turned off before connecting it to or disconnecting it from another fiber, especially when the laser is at power levels above 10 mW.
- All beams should be terminated at the edge of the table, and laboratory doors should be closed whenever a laser is in use.
- Do not place laser beams at eye level.
- Carry out experiments on an optical table such that all laser beams travel horizontally.
- Remove unnecessary reflective items such as reflective jewelry (e.g., rings, watches, etc.) while working near the beam path.
- Be aware that lenses and other optical devices may reflect a portion of the incident beam from the front or rear surface.
- Operate a laser at the minimum power necessary for any operation.
- If possible, reduce the output power of a laser during alignment procedures.
- Use beam shutters and filters to reduce the beam power.
- Post appropriate warning signs or labels near laser setups or rooms.
- Use a laser sign with a lightbox if operating Class 3R or 4 lasers (i.e., lasers requiring the use of a safety interlock).
- Do not use Laser Viewing Cards in place of a proper Beam Trap.
Lasers are categorized into different classes according to their ability to cause eye and other damage. The International Electrotechnical Commission (IEC) is a global organization that prepares and publishes international standards for all electrical, electronic, and related technologies. The IEC document 60825-1 outlines the safety of laser products. A description of each class of laser is given below:
|1||This class of laser is safe under all conditions of normal use, including use with optical instruments for intrabeam viewing. Lasers in this class do not emit radiation at levels that may cause injury during normal operation, and therefore the maximum permissible exposure (MPE) cannot be exceeded. Class 1 lasers can also include enclosed, high-power lasers where exposure to the radiation is not possible without opening or shutting down the laser.|
|1M||Class 1M lasers are safe except when used in conjunction with optical components such as telescopes and microscopes. Lasers belonging to this class emit large-diameter or divergent beams, and the MPE cannot normally be exceeded unless focusing or imaging optics are used to narrow the beam. However, if the beam is refocused, the hazard may be increased and the class may be changed accordingly.|
|2||Class 2 lasers, which are limited to 1 mW of visible continuous-wave radiation, are safe because the blink reflex will limit the exposure in the eye to 0.25 seconds. This category only applies to visible radiation (400 - 700 nm).|
|2M||Because of the blink reflex, this class of laser is classified as safe as long as the beam is not viewed through optical instruments. This laser class also applies to larger-diameter or diverging laser beams.|
|3R||Class 3R lasers produce visible and invisible light that is hazardous under direct and specular-reflection viewing conditions. Eye injuries may occur if you directly view the beam, especially when using optical instruments. Lasers in this class are considered safe as long as they are handled with restricted beam viewing. The MPE can be exceeded with this class of laser; however, this presents a low risk level to injury. Visible, continuous-wave lasers in this class are limited to 5 mW of output power.|
|3B||Class 3B lasers are hazardous to the eye if exposed directly. Diffuse reflections are usually not harmful, but may be when using higher-power Class 3B lasers. Safe handling of devices in this class includes wearing protective eyewear where direct viewing of the laser beam may occur. Lasers of this class must be equipped with a key switch and a safety interlock; moreover, laser safety signs should be used, such that the laser cannot be used without the safety light turning on. Laser products with power output near the upper range of Class 3B may also cause skin burns.|
|4||This class of laser may cause damage to the skin, and also to the eye, even from the viewing of diffuse reflections. These hazards may also apply to indirect or non-specular reflections of the beam, even from apparently matte surfaces. Great care must be taken when handling these lasers. They also represent a fire risk, because they may ignite combustible material. Class 4 lasers must be equipped with a key switch and a safety interlock.|
|All class 2 lasers (and higher) must display, in addition to the corresponding sign above, this triangular warning sign.|
Click to Enlarge
Beam Trap Mounted on a Ø1/2" Post with a Ø1/2" Lens Tube Connected to the Input
- Scatters and Absorbs Laser Beam Energy
- 30 mm Cage System and Ø1/2" Lens Tube Compatible
- 8-32 (M4) Tapped Hole for Post Mounting
Beam traps are common laser lab safety devices that are designed to absorb a laser beam's energy. Versions are offered here that can be used with either CW or pulsed laser beams. Simply align so the beam is directed into the entrance aperture.
These beam traps have internally SM05-threaded input apertures and are 30 mm cage system compatible. A Ø1/2" Lens Tube can be attached directly to the input aperture to shield the laser beam path (see photo to the right). An 8-32 (M4)-tapped hole on the bottom of the beam traps enables post mounting.
Please note that the BT620(/M) contains graphite and may not be suitable for all lab environments. All beam traps will become hot to the touch with beam powers above 10 W.
|Laser Type||Max Average|
|BT600(/M)||200 nm - 3 µm||Anodized Aluminum||CW||80 Wd||150 W/cm2||30 mJ/cm2||2 x 10-4 @ 633 nm||Ø0.43"
|BT610(/M)||400 nm - 2.5 µm||Absorptive Neutral
|CW and Pulsed||30 W||15 W/cm2||40 J/cm2 f||9 x 10-5 @ 633 nm|
|BT620(/M)||1 - 12 µm||Graphite||CW and Pulsed||50 We||25 kW/cm2||25 J/cm2 f||1 x 10-4 @ 633 nm
1 x 10-4 @ 3.39 µm
Click to Enlarge
A BTC30 Beam Trap mounted onto a
30 mm Cage system.
- Scatters and Absorbs Laser Beam Energy
- 30 mm Cage System Compatible
- Quick-Release Flexure Clamping Mechanism for Secure Cage Mounting without Disassembly
- Ø8 mm Clear Aperture
Beam traps are common laser lab safety devices designed to absorb laser beam energy. The Quick-Release Beam Trap offered here is optimized to accept CW laser beams of up to 5 W. It is equipped with a flexure-style clamp that snaps onto any two adjacent cage rods of a preassembled 30 mm cage system. To snap the beam trap onto the rods, ensure that the two 4-40 setscrews (0.050" hex) located on the sides of the trap are loose enough to allow the flexure mechanism to snap over the cage rods. Once positioned, these same two setscrews can be tightened to lock the beam trap's position along the rods. For small positional adjustments, slightly loosen the locking screws and slide the device along the cage rods.
Unlike the beam traps sold above, this beam trap is not equipped with a tap for direct post mounting. Caution should be taken when using this beam trap with laser beams above 2 W, as it will become hot to the touch.
|Item #||Wavelength Range||Absorptive Material||Laser Type||Max Average|
|BTC30||200 nm - 3 µm||Anodized
|CW||5 Wb||150 W/cm2 c||30 mJ/cm2 b||5 x 10-3 @ 633 nm||Ø0.315"
Click to Enlarge
LB2 Beam Block Mounted on a
Ø1/2" Post with a 60 mm Cage System
Click to Enlarge
LB2 Beam Block with
Click for Details
Base of LB2L Beam Block
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LB2L Beam Block with Tubing Connectors
- Visible Beam Block Absorbs up to 10 W CW
- IR Beam Blocks Absorb up to 25 J/cm2 (Pulsed)
- IR Beam Block with Liquid Cooling Available
- Compatible with our LK220 Liquid Chiller
The LB1(/M) Visible Beam Block absorbs CW visible laser beams. It is recommended for a maximum power of 10 W and is shipped pre-mounted on a 3" (75 mm) long, Ø1/2" post. The post is easily interchangeable with other Ø1/2" posts or Ø1" posts with 8-32 (M4) taps.
Our LB2(/M) and LB2L(/M) Beam Blocks absorb CW and pulsed laser beams over the 1 - 12 µm wavelength range. Each unit features a large 1.97" x 1.97" (50.0 mm x 50.0 mm) entrance aperture with a faceplate serves to protect the graphite pad. These beam blocks have 4-40 taps for integration into our 60 mm cage system.
The LB2(/M) IR Beam Block is recommended for use with average powers that do not exceed 80 W (CW) or energy densities that do not exceed 25 J/cm2 (pulsed; performance of individual units may vary due to material properties). It also offers three 8-32 (M4) taps on one side for mounting to Ø1/2" posts or Ø1" posts. The 1.97" x 1.97" (50.0 mm x 50.0 mm) entrance aperture can be widened to 2.72" x 1.97" (69.0 mm x 50.0 mm) by removing the front faceplate using a 1.5 mm hex key (not included).
The LB2L(/M) Beam Block is designed to be liquid cooled, allowing it to handle a maximum average power of 500 W (CW) when used with a 1 L/min water supply at 25 °C. Similar to the LB2(/M) beam block, it can also be used with pulsed sources with energy densities up to 25 J/cm2 (performance of individual units may vary due to material properties). This block has fittings for 1/4" (6 mm) outer diameter hoses; for example, our HPU6 polyurethane hose is compatible with the LB2L block. The one-touch fittings allow the user to easily push the tubing into the connector when attaching a water or coolant supply such as our LK220 liquid chiller. When used with this chiller, the recommended maximum average power is 250 W (CW). The block can withstand pressure up to 145 psi and can be used with water, ethanol-based coolants, or glycol-based coolants, such as our CDTX Coolant. Each unit offers twelve 8-32 (M4) taps, three on each side, for mounting to Ø1/2" posts or Ø1" posts.
Please note that the LB2(/M) and LB2L(/M) beam blocks contains graphite and may not be suitable for all lab environments. All beam traps will become hot to the touch with beam powers above 10 W.
|Laser Type||Max Average
|LB1(/M)||Visible||Steel||CW||10 W||N/A||N/A||1.40" x 0.70"
(35.6 mm x 17.8 mm)
|LB2(/M)||1 - 12 µm||Graphite||CW and Pulsed||80 Wb||25 kW/cm2 c||25 J/cm2 c,d||1.97" x 1.97"
(50.0 mm x 50.0 mm)
|LB2L(/M)||500 We||25 kW/cm2||0 °C to 150 °C||145 psi||1/4" (6 mm)|