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YAG/Harmonics and IR Sensors YAG/Harmonics And IR sensors
YAG/Harmonics And IR sensors
YAG/Harmonics and IR Sensors

Very high damage threshold, large area, laser energy sensors optimized for Nd:YAG, Erbium, Ruby and Holmium lasers.

Coherent YAG/Harmonics and IR EnergyMax sensors are specifically designed for use with very high energy/peak power lasers operating at low repetition rates, such as those based on Nd:YAG, Erbium, Ruby and Ho:YAG. The YAG/Harmonics sensor can operate with laser beams up to 35 mm in diameter, and can work at 1064 nm, 532 nm, 355 nm and 266 nm without the need to change diffusers or any other accessories. The J-50MB-IR sensor is similar to the J-50MB-YAG sensor, except that its diffuser is optimized for long pulse lasers that operate between the range of 500 nm and 2940 nm. It is ideal for long pulse Erbium lasers. The J-25MB-IR sensor has a 25 mm diameter, and can operate throughout the 694 nm to 2.1 µm wavelength range without any reconfiguration.


The YAG/Harmonics and IR EnergyMax Series comprises three different models that work either throughout the visible and near-IR, or throughout the near-IR and mid-IR, without the need to change diffusers. Both these detectors mate Coherent’s unique MaxBlack coating with a novel diffuser to produce superior damage resistance characteristics. This enables operation with lasers that produce very high energy per pulse or very high peak fluences.

The J-50MB-YAG sensor is rated to withstand the following energy densities:

Wavelength Maximum Energy Density
266 nm 1 J/cm2
355 nm 0.8 J/cm2
532 nm 2.8 J/cm2
1064 nm 14 J/cm2

The J-50MB-IR is specifically designed for high damage threshold when used with pulsed lasers used in medical procedures such as Erbium and Holmium lasers. It has a damage threshold in excess of 100 J/cm at 2940 nm with a 100 µs pulse width.

YAG/Harmonics and IR Series products are also “smart” sensors, and incorporate onboard electronics to automatically correct for ambient temperature, as well as built-in wavelength compensation factors. These sensors are compatible with Coherent LabMax-TOP, 3sigma, FieldMaxII-TOP, FieldMaxII-P, EPM1000 and EPM2000 meters.

Both sensors accept an optional heatsink, which can be easily attached by the user to extend the maximum energy or average power range. Specifically, these heat sinks allow the J-25MB-IR sensor to be used up to 15 W average power, and the J-50MB-YAG sensor to be used up to 45 W average power.

The following table outlines the average power handling capability of the sensors when used with optional user installable heat sinks.

Sensor Model Aperture (mm) Wavelength (nm) No Heat sink (W) Small Heat sink (W) Medium Heat sink (W) Large Heat sink (W)
J-50MB-YAG 50 1064 20 NA NA 48
J-25MB-IR 25 1064 20 41 62 NA

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