Novel optical design for improved signal to noise ratio of a real time M-squared measurement Available to Purchase

The basic requirement of an ISO 11146-1(2005) M- square measurement involves measuring the second moment profile of at least five spatial time slices within the first Rayleigh range to establish the beam waist and its location and five spatial time slices beyond the second Rayleigh range to establish the asymptote of the divergence to the focusing lens. Methods have been researched where many spatial time slices can be simultaneously imaged on a single sensor through a little more than two Rayleigh lengths but not with enough signal to noise ratio to extend well beyond the second to fully be ISO 11146-1 compliant. A novel optical delay line has been developed that permits the minimum of five spots beyond the second Rayleigh range with comparable signal to noise as the five spatial time slices within the first Rayleigh range thereby making a fully ISO 11146-1(2005) real time M-square measurement with no moving parts and data acquisition greater than ten frames per second at full resolution. The unique optical approach and measurement technique will be presented in detail in conjunction with a CMOS based two mega pixel GigE sensor that permits use in harsh or robust industrial applications requiring use with robots in a very compact system. The application of this technique can be applied from low power lasers to multi-kilowatt lasers and over the entire spectrum of lasers.