Solutions for up to 80 W or 40 J/cm2 (10 Hz) Beams
Post-Mounted or 30 mm Cage Quick-Release Options Available
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.
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
Thorlabs recommends the use of safety eyewear whenever working with laser beams with non-negligible powers (i.e., > Class 1) 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
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
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Posted Comments:
Poster: s.greveling
Posted Date: 2013-04-04 04:22:03.153
I want to use the BT600/M for a 1064 nm cw laser with a 20 W output. I want to make sure the convection is at a mininum and notice from the specs that with an input power of 40 W the housing is heated over 100 Degrees. What will the heating be with an input power of 20 W?
Poster: tcohen
Posted Date: 2013-04-11 10:18:00.0
Response from Tim at Thorlabs: We have not tested at this power, but after modeling this (assuming 25C ambient) we would expect approximately 70C.
Poster: jlow
Posted Date: 2013-01-18 18:44:00.0
Response from Jeremy at Thorlabs: The LB1 would not function as a beam dump for NIR. It would block the NIR beam but there's nothing to capture the small reflection.
Poster: lundblad
Posted Date: 2012-12-07 12:24:37.353
Can I use the LB1 as a beamdump for 1064 nm?
Poster: tcohen
Posted Date: 2012-05-09 11:15:00.0
Response from Tim at Thorlabs: Thank you for your feedback! The 40J/cm^2 value is representative of a 10ns pulse duration at a 10Hz rep rate. Higher rep rates will decrease the max average energy density and past 20Hz CW values should be used. The different operating mechanisms of the BT600 and BT610 make the BT600 more resistant to CW and the BT610 more resilient against pulsed beams. Although 40J/s is 40W, the BT610 is much more suited to take 40J/cm^2 in a 10ns pulse at 10Hz over one second than it is to handle this average power density in CW operation (400W/cm^2).
Poster: Robert
Posted Date: 2012-05-09 07:26:43.0
Is there a typo in the spec for this? If the beam dump can take 40J/cm2, how come it can only take 15W/cm2 (unless the 40J the total energy for any exposure)? 40 Joules per second would be 40 Watts! Whatever the values are, do they apply to pulses in the nanosecond range?
Poster: Thorlabs
Posted Date: 2010-08-06 16:22:45.0
Response from Javier at Thorlabs to last poster: Thank you for your feedback. We have no tested the maximum power density that the LB1 can withstand. We would recommend using the 10 W guideline specification conservatively.
Poster:
Posted Date: 2010-08-05 10:10:15.0
Hi Thorlabs, for the answer below, what would be the beam dia. for the 10W?
Poster: Thorlabs
Posted Date: 2010-08-03 19:12:10.0
Response from Javier at Thorlabs to last poster: Thank you for your feedback. We do not have precise data for the damage threshold of the black coating on the LB1. However, you can expect deterioration and damage to the coating once the 10 W maximum recommended input is exceeded.
Poster:
Posted Date: 2010-08-03 16:09:57.0
Regarding your LB1, do you have a reference of damage threshold on the black coating?
Poster: Thorlabs
Posted Date: 2010-07-27 09:46:14.0
Response from Javier at Thorlabs to JMStettler: Thank you for your feedback. The links for the drawings and spec sheets of the beam blocks/traps have been fixed. They should work now. I will send you the specification sheet for the BT510.
Poster: JMStettler
Posted Date: 2010-07-26 14:47:02.0
The links for the spec sheets (under "Documents and Drawings") for BT510, BT600, and BT610 all seem to be broken. Where can I find this information?
Under "Beam Trap Specs" I can find some information on the BT600 and BT610, but I dont see anything for the BT510. Is this information anywhere on your website?
Thanks,
JS
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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/cm2b
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
Housing temperature will exceed 100 °C above 40 Watt input power.
Performance of individual units may differ due to material variability.
Total integrated backscatter as a fraction of entrance beam power (@633 nm).
In order to ensure optimum performance, measured from the optical axis in any direction.
@1064 nm (10 ns pulse, 10 Hz repetition rate), performance varies based on material variability.
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
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/cm2b
30 mJ/cm2 a
5 x 10-3
Ø0.315" (Ø8 mm)
Housing temperature will exceed 40 °C above 2 Watt input power
Performance of individual units may differ due to materials variability
Total integrated backscatter as a fraction of entrance beam power (@633 nm)
Large, 1.4" x 0.7" (35.6 mm x 17.8 mm) Target Area
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.