As2S3 and As2Se3 chalcogenide 3-bridges suspended-core fibers(SCFs) are designed with shifted zero-dispersion wavelengths(ZDWs) at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schrodin...As2S3 and As2Se3 chalcogenide 3-bridges suspended-core fibers(SCFs) are designed with shifted zero-dispersion wavelengths(ZDWs) at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schrodinger equation is used to numerically compare supercontinuum(SC) generation in these SCFs pumped at an anomalous dispersion region nearby their ZDWs. Evolutions of the long-wavelength edge(LWE), the power proportion in the long-wavelength region(PPL), and spectral flatness(SF) are calculated and analyzed. Meanwhile, the optimal pump parameters and fiber length are given with LWE, PPL, and SF taken into account. For As2S3 SCFs, SC from a 14 mm-long fiber with a ZDW of 2825 nm pumped at 2870 nm can achieve the longest LWE of - 13 μm and PPL up to ~72%. For As2Se3 SCFs, the LWE of 15.5 μm and the highest PPL of ~ 87% can be achieved in a 10 mm-long fiber with ZDW of 1982 nm pumped at 2000 nm. Although the As2Se3 SCFs can achieve much longer LWE than the As2S3 SCFs, the core diameter of As2Se3 SCFs will be much smaller to obtain a similar ZDW, leading to lower damage threshold and output power. Finally, the optimal parameters for generating SC spanning over different mid-IR windows are given.展开更多
By extending the notion of the minimum distance for linear network error correction code(LNEC), this paper introduces the concept of generalized minimum rank distance(GMRD) of variable-rate linear network error correc...By extending the notion of the minimum distance for linear network error correction code(LNEC), this paper introduces the concept of generalized minimum rank distance(GMRD) of variable-rate linear network error correction codes. The basic properties of GMRD are investigated. It is proved that GMRD can characterize the error correction/detection capability of variable-rate linear network error correction codes when the source transmits the messages at several different rates.展开更多
Let G= (V,A) be adigraph and k ≥ 1 an integer. For u,v ∈ V, we say that the vertex u distance k-dominate v if the distance from u to v at most k. A set D of vertices in G is a distance k-dominating set if each ver...Let G= (V,A) be adigraph and k ≥ 1 an integer. For u,v ∈ V, we say that the vertex u distance k-dominate v if the distance from u to v at most k. A set D of vertices in G is a distance k-dominating set if each vertex of V / D is distance k-dominated by some vertex of D. The distance k-domination number of G, denoted by γk(G), is the minimum cardinality of a distance k-dominating set of G. Generalized de Bruijn digraphs GB(n, d) and generalized Kautz digraphs Gg(n, d) are good candidates for interconnection k networks. Denote △k :=(∑j^k=0 d^j)^-1. F. Tian and J. Xu showed that [n△k] ≤ γk(GB(n,d)) ≤ [n/d^k] and [n△k] ≤ γk(GK(n,d)) ≤ [n/d^k]. In this paper, we prove that every generalized de Bruijn digraph GB(n, d) has the distance k- domination number [n△k] or [n△k] + 1, and the distance k-domination number of every generalized Kautz digraph GK(n, d) bounded above by [n/ (d^k-1 +d^k)]. Additionally, we present various sufficient conditions for γk(GB(n, d)) = [n△k] and γk(GK(n, d)) = [n△k].展开更多
基金Project supported by the National Nature Science Foundation of China(Grant Nos.61435003,61377042,61505024,and 61421002)Open Fund of State Key Laboratory of Advanced Optical Communication Systems and Networks,China(Grant No.2015GZKF004)+1 种基金Open Found of Key Laboratory of Specialty Fiber Optics and Optical Access Networks,Shanghai University,China(Grant No.SKLSFO2014-07)Open Fund of Science and Technology on Solid-State Laser Laboratory,China(Grant No.H04010501W2015000604)
文摘As2S3 and As2Se3 chalcogenide 3-bridges suspended-core fibers(SCFs) are designed with shifted zero-dispersion wavelengths(ZDWs) at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schrodinger equation is used to numerically compare supercontinuum(SC) generation in these SCFs pumped at an anomalous dispersion region nearby their ZDWs. Evolutions of the long-wavelength edge(LWE), the power proportion in the long-wavelength region(PPL), and spectral flatness(SF) are calculated and analyzed. Meanwhile, the optimal pump parameters and fiber length are given with LWE, PPL, and SF taken into account. For As2S3 SCFs, SC from a 14 mm-long fiber with a ZDW of 2825 nm pumped at 2870 nm can achieve the longest LWE of - 13 μm and PPL up to ~72%. For As2Se3 SCFs, the LWE of 15.5 μm and the highest PPL of ~ 87% can be achieved in a 10 mm-long fiber with ZDW of 1982 nm pumped at 2000 nm. Although the As2Se3 SCFs can achieve much longer LWE than the As2S3 SCFs, the core diameter of As2Se3 SCFs will be much smaller to obtain a similar ZDW, leading to lower damage threshold and output power. Finally, the optimal parameters for generating SC spanning over different mid-IR windows are given.
文摘By extending the notion of the minimum distance for linear network error correction code(LNEC), this paper introduces the concept of generalized minimum rank distance(GMRD) of variable-rate linear network error correction codes. The basic properties of GMRD are investigated. It is proved that GMRD can characterize the error correction/detection capability of variable-rate linear network error correction codes when the source transmits the messages at several different rates.
基金Acknowledgements This work was supported in part by the National Natural Science Foundation of China (Grant Nos. 11471210, 11571222, 11601262).
文摘Let G= (V,A) be adigraph and k ≥ 1 an integer. For u,v ∈ V, we say that the vertex u distance k-dominate v if the distance from u to v at most k. A set D of vertices in G is a distance k-dominating set if each vertex of V / D is distance k-dominated by some vertex of D. The distance k-domination number of G, denoted by γk(G), is the minimum cardinality of a distance k-dominating set of G. Generalized de Bruijn digraphs GB(n, d) and generalized Kautz digraphs Gg(n, d) are good candidates for interconnection k networks. Denote △k :=(∑j^k=0 d^j)^-1. F. Tian and J. Xu showed that [n△k] ≤ γk(GB(n,d)) ≤ [n/d^k] and [n△k] ≤ γk(GK(n,d)) ≤ [n/d^k]. In this paper, we prove that every generalized de Bruijn digraph GB(n, d) has the distance k- domination number [n△k] or [n△k] + 1, and the distance k-domination number of every generalized Kautz digraph GK(n, d) bounded above by [n/ (d^k-1 +d^k)]. Additionally, we present various sufficient conditions for γk(GB(n, d)) = [n△k] and γk(GK(n, d)) = [n△k].