Real-time monitoring of thermal lensing of a multikilowatt fiber laser optical system

Abstract

A laser beam waist analyzer system has been developed that permits the real time focal spot measurement of a high power fiber laser in excess of ten of kilowatts and the ability to monitor thermal lensing of a laser and its optical system. The analyzer can provide a laser's spatial profile, circularity, centroid, astigmatism and M-squared values inclusive of the optics used in the process application. The system is very compact, measures in real time with no moving parts by incorporating an all passive optical design to obtain spot diameter, M-squared, Rayleigh length, beam waist position at power levels in excess of 20 kW in less than one second from laser off to laser on.

Phase retrieval algorithm applied to high-energy ultrafast lasers

“…In cases where real-time analysis of optical fields are required, we refer to solutions as proposed in Ref. [45] where multiple defocused intensity signals can be recorded simultaneously. Realtime laser beam characterization (including phase retrieval) is particularly beneficial when high-power amplifiers are considered, and the impact of the thermal loads need to be investigated.…”

Thermo-Optical (TOP) analysis of transmissive elements for laser systems

“…Although analyzed for almost half a century, thermal lensing is an up-to-date topic which increasingly reappears in many fields of laser applications [1][2][3][4][5][6][7][8]. The fast development and the rising number of high brightness lasers with wavelengths around 1 µm brought this topic back to the agenda and requests solutions in processes with narrow process windows.…”

Measurement of M2-Curve for Asymmetric Beams by Self-Referencing Interferometer Wavefront Sensor

“…Now ISO published the latest version of M 2 factor measurement Standard ISO11146-1/2/3 [4,5,6], which standardized laser beam characterization by defining all relevant quantities of laser beams including in measurement method instructions. Now M 2 factor undoubtedly becomes an acceptable characterization parameter for beam quality characterization in the laser community [7,8,9,10,11,12,13,14]. …”