摘要
For decades,a powerful approach to adding data capacity in an optical communication link has been to multiplex independent data-carrying channels and transmit them simultaneously along a fiber.^(1)For example,wavelength-division-multiplexing(WDM)was a key technology in the 1990s and early 2000s to dramatically increase aggregate capacity in a fiber by multiplexing beams of different wavelengths.^(2)For the past roughly 15 years,there has been great promise that space-division-multiplexing(SDM)may bring similar capacity enhancements to optical fiber communications.^(1–3)