Compare Model Drawings, CAD & Specs Availability Price
Thermal Laser Power Sensor, BB Type, 300 mW to 35/250 W, Ø50 mm, 0.19-11 µm
L40(250)A-BB-50 with 12m cable
Thermal Laser Power Sensor, BB Type, 300 mW to 35/250 W, Ø50 mm, 0.19-11 µm with 12m cable


  • Product Name
  • Absorber Type
    BB - Broadband general purpose
  • Aperture Size
    Ø50 mm
  • Spectral Range
    0.19-11 µm
  • Minimum Power
    300 mW
  • Maximum Average Power
    35 W
  • Maximum Power Intermittently
    250 W
  • Minimum Pulse Energy
    100 mJ
  • Maximum Pulse Energy
    4000 J
  • Response Time
    2.5 s
  • Maximum Average Power Density
    10 kW/cm²
  • Maximum Energy Density <100 ns
    0.3 J/cm²
  • Maximum Energy Density 2 ms
    10 J/cm²
  • Cooling
  • Dimensions
    90 x 90 x 33 mm (LxWxD)
  • Cable Length
    1.5 m
  • CE Compliance
  • UKCA Compliance
  • China RoHS Compliance


Measuring Kilowatt Laser Beams with 50W Sensors

For measuring high average powers, you may not need to use a high average power, water-cooled, big and heavy sensor. This video shows you three practical solutions to “get away” with using lower power sensors to measure high power beams, using short exposure times.

Choosing a Thermal Sensor

In this short “Basics” video we review the use – and selection - of thermal sensors for measuring low, medium and high laser powers.

Sensors for Measuring Laser Power

In this short "Basics" video we review in general how one goes about measuring laser beam power, so that you'll have a clear understanding of what the different sensor types are, and when to use each type.

Thermal Power Sensor Accuracy

Ophir former CTO Dr. Ephraim Greenfield discusses the various factors that contribute to uncertainties in measurement when using Ophir laser power and energy meters.

Thermal Sensor Calibration

As the spectral sensitivity of the absorber used for the power and energy measurement is not fully linear, Ophir sensors get a high precision calibration by default with more than one wavelength.

Each thermal sensor is calibrated independently of a particular Ophir power meter with its calibration information contained in the DB15 plug. When the sensor is connected to the meter, the meter reads and interprets this information to display a calibrated reading. Each power meter is calibrated independently and has the same sensitivity as an other meter within about 2 tenths of a percent.

Unless otherwise indicated, Ophir sensors and meters should be recalibrated within 18 months after initial purchase, and then once a year after that.

Absorption of different thermal sensor absorber types
Contact Us illustration

Have questions? Require assistance?

Click below to to contact Ophir Photonics and we'll get back with you shortly.

Contact Ophir Photonics