Analysis and fabrication of tapered multicore gain fibers for high power lasers

Numerical analysis of multicore fiber tapers as a mode area scaling technique for use in coherently combined laser systems is demonstrated. Taper designs are modelled with beam propagation method (BPM) numerical simulations to analyze inter-core crosstalk and mode distortion in centimeter-scale taper transitions. By evaluating taper performance for a range of taper lengths on the scale of centimeters, optimized taper designs can be found for a given MCF design. Tapers based on these simulations are fabricated using a CO2 laser tapering system.