LBS-300HP-NIR Attenuator

The LBS-300HP-NIR is designated for NIR (~1070nm) lasers operating from 500W up to 5KW or up to 50MW/mm².
 
Other wavelengths are also possible to be measured; however the specifications might change because all trials were conducted using 1050-1070 nm lasers.

The LBS-300HP-NIR uses specially treated material that provides extremely low reflection and high laser damage threshold, enabling beam attenuation by around a million times while keeping all beam parameters. This extreme attenuation enables measuring High Power laser beam profile focused on a beam profiler CCD.

A specification defines beam attenuation of a million, meaning less than 0.0001% (1/10⁶) of the beam is reflected towards beam profiler or power meter, however, this parameter can vary from unit to unit. In the majority of units the reflection even less than 0.0001%. The median reflection is 0.000075% and can vary by +/-20% (relative). The exact reflection from each surface is measured during the final production QC and documented in COC supplied with the unit. You can also verify the real reflection of your unit with Ophir support team

Yes, the main function of LBS-300HP-NIR beam splitter is Beam profiling, however it performs a 3-way beam splitting:

Less than 0.0001% (1/10⁶) of the beam is reflected in one direction and less than 0.1 % in another while remaining 99.9% of incident laser beam is transmitted.

This allows user to measure one of the 3 beams, depends on available power measurement equipment and setup convenience.

We recommend operating and storing the LBS-300HP in dust-free conditions, like a regular office or laboratory environment.
Dust and other volatile particles on the wedge surface might cause reflection change and influence the measured beam profile.
Harsh industrial environment operations will require a chamber for isolation.

Any contact with UVFS wedges installed in the LBS-300HP assembly can cause damage and reflection change resulting in beam profile distortion. Thus, it's recommended to avoid even the slightest contact with glass surface with neither hand , paper or cloth.

Operating and storing of LBS-300HP at conditions free of volatile particles, like a regular office or laboratory environment. Harsh industrial environment operations will require isolation.

In case of surface contamination, we recommend contactless cleaning of wedge surface by rinsing it with a chemically pure solvent such as Ethanol, Methanol or IPA (Isopropyl Alcohol), followed by prolonged gentle nitrogen or pure compressed air purging.

Please ensure solvent and gas purity and lack of moisture in order not to contaminate the wedge surface.

If contamination is not removed after cleaning, please consider whether it interferes your laser beam. The spot might be peripheral and not in CA of the laser.

In case the spot is in the laser CA, please contact Ophir support for replacement.

The beam blocker is designated to keep one wedge surface protected during handling and shipping. It can be left attached for low power laser operations. However, in the case of high-power laser irradiation scattered light might interfere with beam profile measurement and cause offset. In case of such offset, we recommend removing the beam blocker.

After removal, an additional laser output, having less than 0.1% of incident beam power will be reflected. That beam could be used for simultaneous measurement of laser power via Ophir Power Meter in addition to beam profiler.

Please use red alignment beam and a C-mount cap with target on it to aim directly to middle of the Input port.

Generally, any beam dump can be used. We recommend using Ophir Beam Dumps with high absorbance at 1070nm and locate it at least 10cm from LBS-300HP to avoid scattered light reaching beam profiler CCD.

Due to such significant attenuation, some light scattered from wedges might interfere correct beam profile measurement and cause offset. Thus, in case the setup allows it we recommend distancing the CCD from wedges by 50, 75 or 100mm C-mount extension tube between LBS-300HP and beam profiler.

Generally, continues usage of LBS-300HP is limited only by temperature increase, thus in case the temperature is mild, there is no limitation.

According to tests, after 10 minutes at 2kW lasing the temperature is increased by 16 Cº and after 4kW lasing increased by 23.4 Cº.

It's not recommended to overheat the LBS-300HP assembly in order not to cause thermal lensing effect of ND filters.

Regular laser safety precautions should apply. Please note, that the main incident beam will exit the LBS-300HP refracted approximately 6°. Provision must be made to safely contain the transmitted beam by beam dump or power meter.

The beam splitter is designated both for CW and pulsed lasers. The allowed energy density of 1064nm pulsed laser should not exceed the equivalent of 15MW/mm².