Wavelength interference or ‘speckle’ has been a persistent problem in laser illumination and metrology for over 60 years – severely limiting the accuracy of measurements and contributing to errors in products that simply cannot be calibrated out. 

What is the solution to a problem which is caused by a system’s own efficiency? After all, laser speckle is caused by the coherence of the beam being so pure a wavelength that it interferes with itself – resulting in the grainy dark and light spots we know as ‘speckle’. Laser optics have been held back by this luminary limitation for too long, and there is only so much that can be achieved by shifting wavelengths or opening up apertures to reduce the peak-to-valley troughs that inhibit optimal accuracy.

Introducing the Cognex In-Sight 3D-L4000: the patented laser profiling vision solution that eliminates the appearance and effects of speckle and produces an extremely straight, clean, bright line which optimises optics.

How does it work? 


The beam utilises a 450 nm blue laser which is steered by a microelectromechanical (MEM) mirror. This mirror acts to sweep the beam back and forth at 26 kHz toward a special diffuser optic. This has the unique effect of diffusing the laser light in one direction in a perfectly uniform fan, while also maintaining a “sheet thickness” equivalent to an undiffused laser beam.

It doesn’t merely mitigate the effects of speckle and fill in the gaps, as it were, but tackles the problem at the source – providing a superior 3D laser scanning inspection system that yields more accurate measurements and boasts an individual frame acquisition rate as low as 26 us.

Pinpoint problems in your manufacturing lines and eliminate inaccuracy with the Cognex In-Sight 3D-L4000 – the next generation in laser optics. Contact the team at Bytronic today.