Laser annealing of silicon dioxide （SiO2） film formed by inductively coupled plasma enhanced chemical vapor deposition （ICPECVD）is studied for the fabrication of low loss silicon based waveguide. The influence of ...Laser annealing of silicon dioxide （SiO2） film formed by inductively coupled plasma enhanced chemical vapor deposition （ICPECVD）is studied for the fabrication of low loss silicon based waveguide. The influence of laser annealing on ICPECVD-deposited SiO2 film is investigated. The surface roughness, refractive index, and etch rate of annealed samples are compared with those of SiO2 film obtained by thermal oxidation. It is demonstrated that the performance of ICPECVD-deposited SiO2 film can be significantly improved by laser annealing. Al2O3/SIO2 waveguide has been fabricated on silicon substrate with the SiO2 lower cladding formed by ICPECVD and laser annealing process, and its propagation loss is found to be comparable with that of the waveguide with thermally oxidized lower cladding.展开更多
The exceptional point(EP)is one of the typical properties of parity–time-symmetric systems,arising from modes coupling with identical resonant frequencies or propagation constants in optics.Here we show that in addit...The exceptional point(EP)is one of the typical properties of parity–time-symmetric systems,arising from modes coupling with identical resonant frequencies or propagation constants in optics.Here we show that in addition to two different modes coupling,a nonuniform distribution of gain and loss leads to an offset from the original propagation constants,including both real and imaginary parts,resulting in the absence of EP.These behaviors are examined by the general coupled-mode theory from the first principle of the Maxwell equations,which yields results that are more accurate than those from the classical coupled-mode theory.Numerical verification via the finite element method is provided.In the end,we present an approach to achieve lossless propagation in a geometrically symmetric waveguide array.展开更多
A novel S-bend with tapered curved waveguides is proposed. The normalized transmitted power is greater than the conventional bend with weakly guided waveguides. Small size and low loss can be reached by the proposed S...A novel S-bend with tapered curved waveguides is proposed. The normalized transmitted power is greater than the conventional bend with weakly guided waveguides. Small size and low loss can be reached by the proposed S-bend.展开更多
Surface plasmon polaritons (SPPs) are the combined electron oscillations and electromagnetic waves propagating along the interface between a conductor and a dielectric. Recently Huck et al. [Huck A, et al. Phys Rev Le...Surface plasmon polaritons (SPPs) are the combined electron oscillations and electromagnetic waves propagating along the interface between a conductor and a dielectric. Recently Huck et al. [Huck A, et al. Phys Rev Lett, 2009, 102: 246802] proved that SPPs can be in a squeezed state, and the squeezed surface plasmons can propagate in a gold waveguide. In this paper, we introduce a quantum mechanical description of the squeezed surface plasmons at first, and discuss the influence of the waveguide losses on the squeezed surface plasmons.展开更多
基金This work was supported by the National Basic Research Program of China （Nos. 2012CB315605 and 2014CB340002）, the National Natural Science Foundation of China （Grant Nos. 61210014,61321004, 61307024, 61574082 and 51561165012）, the High Technology Researeh and Development Program of China（No. 2015AA017101）, the Independent Research Program of Tsinghua University （No. 20131089364） and the Open Fund of State Key Laboratory on Integrated Optoelectronics （Nos. IOSKL2012KF08 and IOSKL2014KF09）.
文摘Laser annealing of silicon dioxide （SiO2） film formed by inductively coupled plasma enhanced chemical vapor deposition （ICPECVD）is studied for the fabrication of low loss silicon based waveguide. The influence of laser annealing on ICPECVD-deposited SiO2 film is investigated. The surface roughness, refractive index, and etch rate of annealed samples are compared with those of SiO2 film obtained by thermal oxidation. It is demonstrated that the performance of ICPECVD-deposited SiO2 film can be significantly improved by laser annealing. Al2O3/SIO2 waveguide has been fabricated on silicon substrate with the SiO2 lower cladding formed by ICPECVD and laser annealing process, and its propagation loss is found to be comparable with that of the waveguide with thermally oxidized lower cladding.
基金National Natural Science Foundation of China(NSFC)(11274083,61405067)Guandong Natural Science Foundation(2015A030313748)Shenzhen Municipal Science and Technology Plan(JCYJ20150513151706573)
文摘The exceptional point(EP)is one of the typical properties of parity–time-symmetric systems,arising from modes coupling with identical resonant frequencies or propagation constants in optics.Here we show that in addition to two different modes coupling,a nonuniform distribution of gain and loss leads to an offset from the original propagation constants,including both real and imaginary parts,resulting in the absence of EP.These behaviors are examined by the general coupled-mode theory from the first principle of the Maxwell equations,which yields results that are more accurate than those from the classical coupled-mode theory.Numerical verification via the finite element method is provided.In the end,we present an approach to achieve lossless propagation in a geometrically symmetric waveguide array.
文摘A novel S-bend with tapered curved waveguides is proposed. The normalized transmitted power is greater than the conventional bend with weakly guided waveguides. Small size and low loss can be reached by the proposed S-bend.
基金supported by the National Basic Research Program of China (Grant No. 2010CB923202)the National Natural Science Foundation of China (Grant No. 10704010)
文摘Surface plasmon polaritons (SPPs) are the combined electron oscillations and electromagnetic waves propagating along the interface between a conductor and a dielectric. Recently Huck et al. [Huck A, et al. Phys Rev Lett, 2009, 102: 246802] proved that SPPs can be in a squeezed state, and the squeezed surface plasmons can propagate in a gold waveguide. In this paper, we introduce a quantum mechanical description of the squeezed surface plasmons at first, and discuss the influence of the waveguide losses on the squeezed surface plasmons.
