Multilayer cladded slab waveguides have been solved by using asymptotic theory once or twice. Based on the solution of a three layer slab waveguide, the wave number of guided modes has been expanded in series of one o...Multilayer cladded slab waveguides have been solved by using asymptotic theory once or twice. Based on the solution of a three layer slab waveguide, the wave number of guided modes has been expanded in series of one or two small parameters. One side cladded slab, two side cladded slab and two parallel cladded slab waveguide system are demonstrated to show how to use this essentially analytic method. Numerical examples have also been given and compared with exact solutions, eved the first or second order solutions are highly accurate.展开更多
We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the di...We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the direct coupling method yield high optical intensity at resonance, which is different from the conventional strategy to create localized "hot spots." The observed excitation efficiency of the Raman signal is significantly enhanced,owing to the high Q factor of the resonant cavity. Furthermore, effective modulation of the Raman intensity is available by adjusting the polymethyl methacrylate(PMMA) thickness in the guiding layer, i.e., by tuning the light–matter interaction length. A large modulation depth is verified through the fact that 10 times variation in the enhancement factor is observed in the experiment as the PMMA thickness varies from 7 to 23 μm.展开更多
Theoretical analysis and numerical results for typical examples are presented for three-layer planar waveguides with nonlinear claddings to find the appropriate structures in which the core electric field can become u...Theoretical analysis and numerical results for typical examples are presented for three-layer planar waveguides with nonlinear claddings to find the appropriate structures in which the core electric field can become uniform at appropriate optical power while the cladding fields decay exponentially . It is shown that there are five kinds of such structures. The electric field profiles are plotted for the five typical examples. We notify that the occurrence of uniform field in a waveguide core may perhaps have prospective applications in waveguide, opto-electronic and photonic devices.展开更多
With the development of manufacturing technology,the propagation loss of the planar waveguide is getting lower and lower,and the shot-noise-limited sensitivity of an HOG will be greatly improved.When the propagation l...With the development of manufacturing technology,the propagation loss of the planar waveguide is getting lower and lower,and the shot-noise-limited sensitivity of an HOG will be greatly improved.When the propagation loss is getting lower,improper coupling-out waveguide in the waveguide coil may lead to non-ignorable bending loss and crosstalk because of the small radius of curvature and X-junction.In this paper,different couplingout waveguides have been designed.After calculation and optimization by the beam propagation method,we found the proper coupling-out waveguide having relatively low propagation loss,which can improve the sensitivity of the HOG.展开更多
文摘Multilayer cladded slab waveguides have been solved by using asymptotic theory once or twice. Based on the solution of a three layer slab waveguide, the wave number of guided modes has been expanded in series of one or two small parameters. One side cladded slab, two side cladded slab and two parallel cladded slab waveguide system are demonstrated to show how to use this essentially analytic method. Numerical examples have also been given and compared with exact solutions, eved the first or second order solutions are highly accurate.
基金supported by the Natural Science Foundation of Jiangsu Province(Nos.BK20140246 and BK20160417)the National Natural Science Foundation of China(No.61371057,61601251,11404092,and61701261)+1 种基金the China Postdoctoral Science Foundation Funded Project(No.2016M601586)the Fundamental Research Funds for the Central Universities(No.2017B14914)
文摘We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the direct coupling method yield high optical intensity at resonance, which is different from the conventional strategy to create localized "hot spots." The observed excitation efficiency of the Raman signal is significantly enhanced,owing to the high Q factor of the resonant cavity. Furthermore, effective modulation of the Raman intensity is available by adjusting the polymethyl methacrylate(PMMA) thickness in the guiding layer, i.e., by tuning the light–matter interaction length. A large modulation depth is verified through the fact that 10 times variation in the enhancement factor is observed in the experiment as the PMMA thickness varies from 7 to 23 μm.
基金This work was partially supported by the Paper Foundation of Northern Jiaotong University.
文摘Theoretical analysis and numerical results for typical examples are presented for three-layer planar waveguides with nonlinear claddings to find the appropriate structures in which the core electric field can become uniform at appropriate optical power while the cladding fields decay exponentially . It is shown that there are five kinds of such structures. The electric field profiles are plotted for the five typical examples. We notify that the occurrence of uniform field in a waveguide core may perhaps have prospective applications in waveguide, opto-electronic and photonic devices.
基金Project supported by the National Natural Science Foundation of China(Nos.61274066,61504138,61474115)the National Key Research and Development Program of China(No.2016YFA02005003)
文摘With the development of manufacturing technology,the propagation loss of the planar waveguide is getting lower and lower,and the shot-noise-limited sensitivity of an HOG will be greatly improved.When the propagation loss is getting lower,improper coupling-out waveguide in the waveguide coil may lead to non-ignorable bending loss and crosstalk because of the small radius of curvature and X-junction.In this paper,different couplingout waveguides have been designed.After calculation and optimization by the beam propagation method,we found the proper coupling-out waveguide having relatively low propagation loss,which can improve the sensitivity of the HOG.