| Item # | Laser Input | Max Average Power | Type |
|---|---|---|---|
| BT600(/M) | CW | 80 W | Trap |
| BT640(/M) | CW & Pulsed | 30 W | Trap |
| BTC30 | CW | 5 W | Trap |
| LB1(/M) | CW | 10 W | Block |
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. Beam blocks are ideal for lower power CW applications (<10 W), while our post-mounted beam traps are suitable for higher power CW (BT600) or pulsed (BT610) beams. A quick-release trap option is also available; suitable for 5 W CW lasers, this beam trap can be easily inserted into and removed from existing 30 mm cage systems without disassembly.
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.
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:
| Class | Description | Warning Label |
|---|---|---|
| 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 | 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 are limited to 5 mW of output power in this class. | ![]() |
| 3B | Class 3B lasers are hazardous to the eye if exposed directly. However, diffuse reflections are not harmful. Safe handling of devices in this class includes wearing protective eyewear where direct viewing of the laser beam may occur. In addition, laser safety signs lightboxes should be used with lasers that require a safety interlock so that the laser cannot be used without the safety light turning on. Class-3B lasers must be equipped with a key switch and a safety interlock. | ![]() |
| 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 | ![]() | |
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. Each beam trap comes with one removable TR3 (TR75/M) post for mounting.
These beam traps have internally SM05-threaded input apertures and are 30 mm cage system compatibile. An SM05 Lens Tube can be attached directly to the input aperture to shield the laser beam path (see photo to the right).
| Item # | Wavelength Range | Laser Type | Max Average Power | Max Average Power Density | Max Average Energy Density | Backscatterc | Entrance Aperture | Max Acceptance Angled |
|---|---|---|---|---|---|---|---|---|
| BT600(/M) | 200 nm to 3 µm | CW | 80 Wa | 150 W/cm2 b | 30 mJ/cm2 | 2 x 10-4 | Ø0.43" (Ø11 mm) |
±5° |
| BT610(/M) | 400 nm to 2.5 µm | CW and Pulsed | 30 W | 15 W/cm2 | 40 J/cm2 (10 Hz)e | 9 x 10-5 |
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
BT600 |
Beam Trap, 150 W/cm2 CW Max Avg. Power, 3" Post Included |
$229.50 |
Today |
BT610 |
Beam Trap, 40 J/cm2 10 Hz Max Avg. Energy, 3" Post Included |
$290.00 |
Today |
BT600/M |
Beam Trap, 150 W/cm2 CW Max Avg. Power, 75 mm Post Included, Metric |
$229.50 |
Today |
BT610/M |
Beam Trap, 40 J/cm2 10 Hz Max Avg. Energy, 75 mm Post Included, Metric |
$290.00 |
Today |
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 | Laser Type | Max Average Power | Max Average Power Density | Max Average Energy Density | Backscatterc | Entrance Aperture |
|---|---|---|---|---|---|---|---|
| BTC30 | 200 nm to 3 µm | CW | 5 Wa | 150 W/cm2 b | 30 mJ/cm2 a | 5 x 10-3 | Ø0.315" (Ø8 mm) |
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
BTC30 |
Customer Inspired!30 mm Cage-Compatible, Quick-Release Beam Trap, 5 W CW Max Avg. Power |
$199.00 |
Today |

The LB1 beam block absorbs CW visible laser beams. It is recommended for a maximum power of 10 W. These beam blocks are 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.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LB1 |
Beam Block (Active Area: 0.7" X 1.4"), Includes TR3 Post |
$48.50 |
Today |
LB1/M |
Beam Block (Active Area: 18 mm X 36 mm), Includes TR75/M Post |
$48.50 |
Today |