Measuring Challenges of Wide and Divergent Beams

Article by: Yoni Groisman, Karol Sanilevitch, Roei Yiftah, Dr. Simon Rankel

VCSELs, LEDs, edge emitting, and fiber lasers are used in many sensitive applications within fast-growing markets. To guarantee the high quality of the devices, it is essential to analyze the beam profile, but those wide, divergent beams place specific requirements on the measurement system.

Measuring Challenges

On the one hand, the apertures of conventional beam profilers are too small to collect the entire spot of large or divergent light sources.
On the other hand, diverging beams cannot be accurately measured with regular detectors because the quantum efficiency of the detector is highly dependent on the angle of incidence.

These challenges have now been addressed with the development of the Ophir Wide Beam Imager – WB-I, a calibrated optical accessory for beam profiling cameras, based on diffuser with 45mm diameter aperture and a CCTV lens that is designated for far field measurement.

By developing the WB-I accessory, Ophir simplified the measurement of widely divergent light sources. VCSELs and LEDs can now be easily measured within the production process, in R&D, and at customer sites.

The combination of the WB-I instrument with a beam profiler camera and the BeamGage software quickly delivers reliable measurement results. Far-field beam profiling of diverging or wide sources no longer requires extensive preparation or individually built equipment but can be performed with a calibrated measurement device.

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