Broadband 15-Mode Multiplexers based on Multi-Plane Light Conversion with 8 Planes in Unwrapped Phase Space

We present a compact 15-mode multi-plane light conversion device with a linear fiber array input, Hermite-Gaussian modes output, 8 phase masks and 8? phase wraps to enable 200 nm operation bandwidth with significantly reduced wavelength dependence compared to traditional 2? designs.