Design optimization of flattop interleaver and its dispersion compensation

Abstract

Abstract:The objective of this paper is to present a general strategy for design optimization of flattop interleavers, and dispersion compensation for the interleavers, in order to achieve superior optical performance. The interleaver is formed by two multi-cavity Gire-Tournois etalons (MC-GTE) in a Michelson Interferometer (MI). An interleaver that has m cavities in one etalon and n cavities in the other is called an mn-GTE interleaver. Our optimization strategy exploits the general flattop condition and the technique of ripple equalization. Any mn-GTE interleaver may be optimized. The spectral performance can be greatly improved by the optimization process. As an illustration, we present a comprehensive analysis for a 11-GTE and a 21-GTE interleaver. The analytical expressions for flattop conditions, peak and trough positions are derived for optimization. The optimal performance of the interleavers can be controlled by the reflection coefficients and the parameters m and n. To achieve lowdispersion mn-GTE flattop interleavers, we propose to use one additional MC-GTE as a dispersion compensator to compensate for the chromatic dispersion. The analytical expressions of group delays and chromatic dispersions for an MC-GTE interleaver are derived. The optimization strategy of dispersion-ripple equalization is explained. The results show that the dispersion performance can be tailored by changing the reflection coefficients of the MC-GTE, and the dispersion and bandwidth can be enhanced by increasing the number of cavities of the MC-GTE.

Novel Liquid Crystal Tunable Flat-Top Optical Interleaver

“…These two GTIs can be either single-cavity [4,9] or multicavity GTIs [3]. The second GTI is used to improve the dispersion and spectral response performance [3].…”

“…Consequently, for M and N reflectors, the general expression for the unity transmission condition to find the reflective factors is [3] 2…”

“…However, conventional filters, like the thin-film based filters to separate such channels by 50 GHz, become cost prohibitive at narrow bandwidths. A critical reason for that is the poor fabrication yields, which leads to higher cost [3]. Optical interleavers provide the means to more effective devices for filtering dense wavelength channels [3][4][5][6][7][8][9][10][11][12].…”

“…An example of effective optical interferometer is the combination of Michelson interferometer and Gires-Tournois interferometers (MI-GTI) [3][4][5][6][7][8][9][10][11][12]. In this configuration, the Gires-Tournois interferometer is used as a phase dispersive mirror to replace one or both of the mirrors in the Michelson interferometer.…”

Design and Analysis of an all-fiber MZI Interleaver Based on Fiber Ring Resonator

“…The main types of interleavers include methods of all-fiber Mach-Zehnder interferometer(MZI) [3][4][5][6] , Gires-Tournoise interferometer [7][8] , Fabry-Perot interference filter(F-P) [9] , photonic crystal [10] and so on. Among the abovementioned interleavers, all-fiber MZI interleaver based on fused fiber interferometer exhibits special qualities with even channel, simple structure and low insertion loss.…”