Cd. Poole et al., OPTICAL FIBER-BASED DISPERSION COMPENSATION USING HIGHER-ORDER MODES NEAR CUTOFF, Journal of lightwave technology, 12(10), 1994, pp. 1746-1758
Higher order spatial modes in optical fibers exhibit large, negative c
hromatic dispersion when operated near their cutoff wavelength. By usi
ng a spatial mode-converter to selectively excite a higher order mode
in specially designed multimode fiber, this dispersion can be used to
compensate the positive dispersion in conventional single-mode fiber s
pans. In this paper, issues related to compensating fiber and mode-con
verter design are explored. Experimental measurements in specially des
igned two-mode fibers operated in LP11 mode show negative dispersion a
s large as -770 ps/nm.km at 1555 nm. Pulse propagation and system expe
riments employing spatial mode-converters to excite LP11 mode in a two
-mode fiber demonstrate the feasibility of this technique for dispersi
on compensation in lightwave systems.