PowerMax-Pro sensors

Coherent has released a new type of laser power sensing detector that combines the broad wavelength sensitivity, dynamic range and laser damage resistance of a thermopile with the response speed of a semiconductor photodiode. The detector relies on a novel, thin-film technology to create a device which rapidly senses thermal changes due to incident laser energy.

Unlike traditional thermopile detectors, in these PowerMax-Pro sensors, heat flows vertically through a film which is only microns thick, rather than radially to the edge of the device over a distance of several centimetres. The result is a measurement response time less than 10µs, as compared to more than 1 second for traditional thermopiles. Plus, these detectors can operate over a spectral range as broad as 300nm to 11µm, and incorporate a large 30 x 30mm active area.

The high response speed of PowerMax Pro sensors is particularly advantageous in commercial applications, where it enables CW laser power and pulsed laser energy to be sampled much more frequently, resulting in increased throughput and improved process control. And, their broad spectral response and large active area make these detectors useful with virtually all commercial, scientific, and medical lasers operating in the visible, near infrared and far infrared, including CO2 lasers at 10.6µm. 

The PowerMax-Pro product offering includes two coatings: a broadband coated model, which operates from 300nm to 11 µm, and a high damage threshold (up to 14kW/cm²) model, which covers both 300nm to 1,100nm and 9.5µm to 11µm. All models cover the power range of 50mW to 150W with a noise equivalent power of less than 5mW in water-cooled and fan-cooled configurations. The sensors can also be operated convectively with passive air cooling.