Ophir Photonics, global leader in precision laser measurement equipment and a Newport Corporation brand, today announced a new system for narrowband optical power measurement, the 3A-IS Optical Power Sensor and AUX-LED Self-Absorption Accessory. The 3A-IS is a compact, easy-to-use integrating sphere and photodiode sensor system. It is designed to measure the optical power of divergent, narrowband light sources from 350nm-1100nm, such as lasers and LEDs. The AUX-LED is an accessory for the 3A-IS that corrects the effects of self-absorption.
The 3A-IS power detector has a unique design that uses two 40mm integrating spheres in series, and a photodiode detector. The light intensity on the sensor is significantly reduced, allowing measurement of powers up to 3W power, well beyond the powers measurable by standard photodiodes.
The AUX-LED is a current regulated LED source that provides a self-absorption correction when measuring UV-LEDs operating in the 365nm-400nm range. Additional AUX-LED wavelengths are available on request for specific UV, visible, and IR wavelengths.
"Self-absorption in integrating sphere measurements is a well-known issue," said Dr. Efi Rotem, Project Manager at Ophir Photonics. "The device under test disturbs the geometry and throughput of the sphere by absorbing or reflecting some of the light inside, which causes a measurement error. This problem is solved using an auxiliary lamp installed inside the sphere.
Measurement of the auxiliary lamp before and after the device under test is in place, enables to correct the effect of self-absorption. Spectrometer based systems require a wide band auxiliary lamp such as a tungsten lamp to cover the entire spectral range of the spectrometer."
When using the 3A-IS for measuring narrowband sources with a known wavelength, the auxiliary lamp should also have the same spectral characteristics as the device under test. The AUX-LED replaces a wideband auxiliary lamp with a LED for a specific wavelength band such as UV-LEDs at 365nm-400nm, IR-LEDs at 800nm-850nm, etc.
The 3A-IS power meter feature a "Smart Connector" interface that operates with the company's StarLite, Nova II, and Vega smart displays, and Juno PC interface. The display is automatically configured and calibrated when plugged into one of the company's laser measurement heads.