Existence of out-of-plane conical dispersion for a triangular photonic crystal lattice is reported. It is observed that conical dispersion is maintained for a number of out-of-plane wave vectors（k;）. We study a case...Existence of out-of-plane conical dispersion for a triangular photonic crystal lattice is reported. It is observed that conical dispersion is maintained for a number of out-of-plane wave vectors（k;）. We study a case where Dirac like linear dispersion exists but the photonic density of states is not vanishing, called Dwarf Dirac cone（DDC） which does not support localized modes. We demonstrate the trapping of such modes by introducing defects in the crystal. Interestingly, we find by k-point sampling as well as by tuning trapped frequency that such a conical dispersion has an inherent light confining property and it is governed by neither of the known wave confining mechanisms like total internal reflection, band gap guidance. Our study reveals that such a conical dispersion in a non-vanishing photonic density of states induces unexpected intense trapping of light compared with those at other points in the continuum. Such studies provoke fabrication of new devices with exciting properties and new functionalities.展开更多
This paper presents a novel in-plane photonic crystal channel drop filter. The device is composed of a resonant cavity sandwiched by two parallel waveguides. The cavity has two resonant modes with opposite symmetries....This paper presents a novel in-plane photonic crystal channel drop filter. The device is composed of a resonant cavity sandwiched by two parallel waveguides. The cavity has two resonant modes with opposite symmetries. Tuning these two modes into degeneracy causes destructive interference in bus waveguide, which results in high forward drop efficiency at the resonant wavelength. From the result of numerical analysis by using two-dimensional finite-difference time-domain method, the channel drop filter has a drop efficiency of 96% and a Q value of over 3000, which can be used in dense wavelength division multiplexing systems.展开更多
基金supported by Director,CSIR-CGCRI,the DST,Government of Indiathe CSIR 12th Plan Project(GLASSFIB),India
文摘Existence of out-of-plane conical dispersion for a triangular photonic crystal lattice is reported. It is observed that conical dispersion is maintained for a number of out-of-plane wave vectors（k;）. We study a case where Dirac like linear dispersion exists but the photonic density of states is not vanishing, called Dwarf Dirac cone（DDC） which does not support localized modes. We demonstrate the trapping of such modes by introducing defects in the crystal. Interestingly, we find by k-point sampling as well as by tuning trapped frequency that such a conical dispersion has an inherent light confining property and it is governed by neither of the known wave confining mechanisms like total internal reflection, band gap guidance. Our study reveals that such a conical dispersion in a non-vanishing photonic density of states induces unexpected intense trapping of light compared with those at other points in the continuum. Such studies provoke fabrication of new devices with exciting properties and new functionalities.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10774195,U0834001,and 10974263)the Ministry of Education,China (Grant No.309024)+1 种基金the Program for New Century Excellent Talents in University,Chinathe National Basic Research Program of China (Grant No.2010CB923201)
文摘This paper presents a novel in-plane photonic crystal channel drop filter. The device is composed of a resonant cavity sandwiched by two parallel waveguides. The cavity has two resonant modes with opposite symmetries. Tuning these two modes into degeneracy causes destructive interference in bus waveguide, which results in high forward drop efficiency at the resonant wavelength. From the result of numerical analysis by using two-dimensional finite-difference time-domain method, the channel drop filter has a drop efficiency of 96% and a Q value of over 3000, which can be used in dense wavelength division multiplexing systems.
