Laser Power Sensor Guide

Accurate and Reliable Laser Power Measurement Solutions for 35 Years

For over 35 years, Newport has met the challenge to consistently provide accurate and reliable optical measurement solutions such as Laser Power Sensors. We offer a wide range of calibrated thermoplile laser power sensors for use with Newport or Ophir Optical Power Meters.

Thermopile Laser Power Sensor Basics

A Thermopile is an electronic device that converts themal energy into electrical energy. Thermopiles are composed of multiple thermocouples and generate a voltage proportional to a local temperature gradient. Thermopile based laser power sensors respond slowly to laser beam inputs but can handle high optical power making them suitable for measuring the average power of CW or pulsed lasers. For more information on Thermoplie based laser power sensors, please refer to our Thermopile Laser Power Sensor Technology Guide.

Selecting a Laser Power Sensor

Optical Power and Energy Meter Compatibility

Our Laser Power Sensors come with a DB15 connector and are calibrated for use with either Newport Brand optical power and energy meters like the 1918-R , 843-R , 1936-R and 2936-R , or for use with Ophir Brand optical power and energy meters like the NOVA-II and VEGA . Please refer to the brand compatibility tables below to choose a laser power sensor that will work with your Newport or Ophir Optical Power Meter.

Maximum Optical Power Requirements

In general, thermopile laser sensors can be divided into three power input ranges. High Sensitivity Thermopile Sensors are capible of measuring at µW levels, replacing photodiode sensors in some applications. Low to Medium Power General Purpose Thermopile Sensors are capable of measuring laser power in the mid mW to 500 W range. Water Cooled Thermopile Sensors are designed for very high power applications up to 5 kW. Please refer to the brand compatibility tables below to select the proper power range for your laser.

Beam Diameter at Sensor

The size of your laser beam at the sensor head is an important criteria for laser power sensor selection. This dimension will determine the appropriate sensor active diameter. It is preferred to use a thermopile sensor with an active diameter sufficient to contain the entire beam without the use of additional optics. You should chose a sensor active diameter that is between 10% and 30% larger than your beam diameter to allow for ease of beam alignment and positioning. You can select the active diameter, power range requirement, and power meter compatibility using the tables below. Popular active diameters include: 12mm, 17mm, 35mm, and 50mm.

Maximum Power Density

Themopile sensors can be damaged if their maximum power density rating is exceeded. For CW Lasers, Power Density = Beam Power (W) / (0.785 x Beam Diameter2 (cm)). For example, a 100 W beam with a 2 mm diameter has a power density of 3.184 kW/cm2. We recommend that you measure your beam in a place where it is not highly focused to reduce the power density, and choose a sensor with a damage threshold value rating that exceeds your maximum power density requirements by at least 65%.

Newport Power Meter Compatible Laser Power Sensors

Series Active Diameter Features and Benefits
919P-10A-sensors 919P Series Thermopile Sensors 9.5 - 65 mm • Broadband flat spectral response from 0.19–11 µm
• NIST-traceable calibration included
• Insensitive to beam position
• Compatible with the new 843-R power meter
• Calibrated at 532, 1064, and 10600 nm (except for 919P-5kW-50)

Ophir Power Meter Compatible Laser Power Sensors (Sold in US & Canada only)

Series Active Diameter Features and Benefits
7Z02637 Low Power Thermopile Sensors High Sensitivity Thermopile Sensors
9.5mm
12mm
• Measure 30 µW to 12 W optical power
• Compatible with Ophir power meters
Low Power Thermopile Sensors
16mm
17.5mm
26mm
• Measure up to 30 W optical power
• Compatible with Ophir power meters
7Z02722 Medium Power Thermopile Sensors 17mm
26mm
35mm
50mm
• Measure up to 500 W optical power
• Compatible with Ophir power meters
• Sensor Body, Heatsink, or Fan Cooling
7Z02119 Water Cooled Thermopile Sensors 50mm • Measure up to 5 kW optical power
• Compatible with Ophir power meters
• Water cooled