Figure 2
WDM transmission over a FMF link experiment. (a) Experimental setup. Two light waves with 100-GHz channel spacing are coupled into a FMF through a mode-selective photonic lantern. The target channel at a longer wavelength is modulated by two tones and launched into the LP01 mode. The interfering channel is modulated by a single tone and launched into one of the four mode groups: LP01, LP11, LP21 and LP02. The inset illustrates the generation of nonlinear crosstalk due to four-wave mixing. (b,c) Cross-sectional image and refractive-index profile of the 6-mode FMF. (d) Output mode intensity profiles after transmission through the FMF. (e) Impulse response of the FMF excited by different input modes. LD, laser diode; MZM, Mach–Zehnder modulator; OA, optical amplifier; OC, optical circulator; PC, polarization controller; PD, photodetector; VOA, variable optical attenuator.
