Fig. 10: Photonic lantern losses to free-space and to fiber.

a Output power loss vs wavelength per input mode. b Output power following butt-coupling to a 6-mode fiber. c IR images of the PL from a top view for identifying scattering, with each input excited and significant points on the PL marked on the images. d IR images of the section "F"-"A" with higher exposure time. e Microscope image of the PL butt coupled to the fiber