Acoustooptic Characterization of a Birefringent Two-Mode Photonic Crystal Fiber

Abstract

Abstract:The effect of axial variations in acoustooptic phase-mismatch coefficient of a two-mode birefringent photonic crystal fiber (PCF) is studied experimentally using two different methods. The first method is to determine axial non-uniformities directly from the transmission spectrum, while the second method is to use acoustic pulses. Both methods are seen to be in good agreement. It is found that axial non-uniformities increase the coupling bandwidth significantly as compared to an axially uniform fiber. The effect of acoustic birefringence is also considered.

Combined effects of optical and acoustic birefringence on acousto-optic mode coupling in photonic crystal fiber

“…Since the distortion of the filter spectrum will severely limit the practical applications of the filters, it is important to determine the origin of the phenomena and find ways to control it. It has been speculated that the origin of such distorted filter spectra is the refractive index splitting between nearly degenerate higher-order modes and/or the axial non-uniformities of the fiber [12,13]. However, no systematic analysis has been reported to quantitatively explain the observed filter behavior, to the best of our knowledge.…”