Breakthrough In Detector Technology Delivers High Speed Laser Measurement

A dramatic technological advancement in laser power sensing from Coherent Inc. has yielded a completely new type of 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 new PowerMax-Pro sensors (Patent Pending), 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 centimeters. The result is a measurement response time below10 µs, as compared to over 1 second for traditional thermopiles. Plus, these detectors can operate over a spectral range as broad as 300 nm to 11 µm, and incorporate a large 30 mm x 30 mm 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 10.6 µm.

The new PowerMax-Pro product offering includes two coatings - a broadband coated model, which operates from 300 nm to 11 µm, and a high damage threshold (up to 14 kW/cm²) model, which covers both 300 nm to 1100 nm and 9.5 µm to 11 µm. All  models cover the power range of 50 mW to 150W with a noise equivalent power of less than5mW in water-cooled and fan-cooled configurations. The sensors can also be operated convectively with passive air cooling.

About Coherent, Inc.
Founded in 1966, Coherent, Inc. is a world leader in providing photonics based solutions to the commercial and scientific research markets, and is part of the Standard & Poor’s SmallCap 600 Index and the Russell 2000. For more information, visit http://www.Coherent.com.