Accurate measurement of the dispersion of hollow-core fibers using a scalable technique

Abstract

A scalable and accurate technique for measuring the group index and dispersion of optical fibers is used to provide the first accurate measurements of dispersion slope in hollow-core photonic band-gap fibers. We present data showing group index, group-velocity dispersion and dispersion slope in hollow-core fibers guiding at both 800 nm and 1064 nm wavelength.

Negative Curvature Hollow-Core Optical Fiber

“…The flat and shallow dispersion slope changes rapidly at wavelengths near band edges where cladding modes couple with the core mode. As in HC-PBG, the strong coupling interaction at the band edges causes the group dispersion across the transmission window to change from anomalous to normal towards shorter wavelengths [64]. Near the band edge, the value of group velocity dispersion rises rapidly up to hundreds of ps/(km × nm).…”

Spectral Difference Interferometry for the Characterization of Optical Media

“…Measuring such a length of fiber, which has a net dispersion of , would present a challenge if undertaken using a Mach–Zehnder interferometric scheme, requiring a very long delay line to provide a reference wave. Because of this, many interferometric measurements of the chromatic dispersion of fiber are performed on very short lengths (at most in the meters regime) of the sample . As such, measurements of such short samples can only give an estimate of the actual dispersion of the full length of test fiber meaning direct measurements must be used if accuracy is important.…”

“…Because of this, many interferometric measurements of the chromatic dispersion of fiber are performed on very short lengths (at most in the meters regime) of the sample. [11,12] As such, measurements of such short samples can only give an estimate of the actual dispersion of the full length of test fiber meaning direct measurements must be used if accuracy is important. Figure 5 shows the results of this measurement (solid orange line) plotted alongside an empirical formula (dashed blue lines) provided by Corning to estimate the chromatic dispersion of SMF-28:…”

Experimental measurement and numerical calculation of dispersion of ZBLAN fiber

“…Interferometric techniques do not require pulse detection but do provide the equivalent 1 ps time resolution which is several orders of magnitude better than time-off light measurements, and is sufficient to characterize fibers shorter than 1m. [9,10] Based on above analysis, the interferometric method provides most accurate results and needs shortest length of tested fiber. So here we adopted this method to measure the dispersion of ZBLAN fiber.…”