The surface mode propagation along a dielectric slab waveguide which consists of the core and substrate of right handed materials (RHM) and the cover of left handed materials (LHM) is studied. The normalized frequency...The surface mode propagation along a dielectric slab waveguide which consists of the core and substrate of right handed materials (RHM) and the cover of left handed materials (LHM) is studied. The normalized frequency and normalized propagation constant are introduced to the left-handed material slab waveguides. The dispersion relations expressed by the normalized parameters are derived. Universal dispersion curves are obtained analytically. Based on that, the dispersion properties differ dramatically for different LHM constitutive parameters, the surface TE0 and TE1 modes are internatively obtained. It shows that two different kinds of TE modes compensate each other to form a whole mode.展开更多
Reactive ion etching（RIE） of LiNbO_3（LN） in SF_6 plasma atmosphere was studied for optimizing the preparation conditions for LN ridge waveguides.The samples to be etched are Ti-diffused LN slab waveguides overlaid...Reactive ion etching（RIE） of LiNbO_3（LN） in SF_6 plasma atmosphere was studied for optimizing the preparation conditions for LN ridge waveguides.The samples to be etched are Ti-diffused LN slab waveguides overlaid with a chromium film mask that has a Mach-Zehnder interferometer（MZI） array pattern.The experimental results indicate that the LN-etching rate（R_（LN）） and the Cr-etching rate（R_（Cr）） as well as the rate ratio R_（LN）/R_（Cr） increase with either increasing the radio-frequency（RF） power at a given SF_6 flow rate or increasing the SF_6 flow rate at a fixed RF power.The maximum values of R_（LN） = 43.2 nm/min and R_（LN）/R_（Cr） = 3.27 were achieved with 300 W RF power and 40 sccm SF_6 flow.When the SF_6 flow rate exceeds 40 sccm,an increase in the flow rate causes the etching rates and the rate ratio to decrease.The scanning electron microscope images of the LN ridge prepared after～20 min etching show that the ridge height is 680 nm and the sidewall slope angle is about 60°.展开更多
The results presented here show for the first time the experimental demonstration of the fabrication of lossy mode resonance(LMR) devices based on perovskite coatings deposited on planar waveguides. Perovskite thin fi...The results presented here show for the first time the experimental demonstration of the fabrication of lossy mode resonance(LMR) devices based on perovskite coatings deposited on planar waveguides. Perovskite thin films have been obtained by means of the spin coating technique and their presence was confirmed by ellipsometry, scanning electron microscopy, and X-ray diffraction testing. The LMRs can be generated in a wide wavelength range and the experimental results agree with the theoretical simulations. Overall, this study highlights the potential of perovskite thin films for the development of novel LMR-based devices that can be used for environmental monitoring, industrial sensing, and gas detection, among other applications.展开更多
基金supported by National Natural ScienceFoundation of China (Grant No. 60577043 and 60571054)Creative Graduate Student Foundation of Shanghai Uni-versity (Grant No. 080153).
文摘The surface mode propagation along a dielectric slab waveguide which consists of the core and substrate of right handed materials (RHM) and the cover of left handed materials (LHM) is studied. The normalized frequency and normalized propagation constant are introduced to the left-handed material slab waveguides. The dispersion relations expressed by the normalized parameters are derived. Universal dispersion curves are obtained analytically. Based on that, the dispersion properties differ dramatically for different LHM constitutive parameters, the surface TE0 and TE1 modes are internatively obtained. It shows that two different kinds of TE modes compensate each other to form a whole mode.
基金supported by the National Natural Science Foundation of China(No.61078039)
文摘Reactive ion etching（RIE） of LiNbO_3（LN） in SF_6 plasma atmosphere was studied for optimizing the preparation conditions for LN ridge waveguides.The samples to be etched are Ti-diffused LN slab waveguides overlaid with a chromium film mask that has a Mach-Zehnder interferometer（MZI） array pattern.The experimental results indicate that the LN-etching rate（R_（LN）） and the Cr-etching rate（R_（Cr）） as well as the rate ratio R_（LN）/R_（Cr） increase with either increasing the radio-frequency（RF） power at a given SF_6 flow rate or increasing the SF_6 flow rate at a fixed RF power.The maximum values of R_（LN） = 43.2 nm/min and R_（LN）/R_（Cr） = 3.27 were achieved with 300 W RF power and 40 sccm SF_6 flow.When the SF_6 flow rate exceeds 40 sccm,an increase in the flow rate causes the etching rates and the rate ratio to decrease.The scanning electron microscope images of the LN ridge prepared after～20 min etching show that the ridge height is 680 nm and the sidewall slope angle is about 60°.
基金the partial support to Agencia Estatal de Investigación PID2019-106231RB-I00 research projectUniversidad Rey Juan Carlos with research project “Células fotovoltaicas de tercera generación basadas en semiconductores orgánicos avanzados perovskitas híbridas en estructuras multiunión” (reference M2607)the pre-doctoral research grant of the Public University of Navarra。
文摘The results presented here show for the first time the experimental demonstration of the fabrication of lossy mode resonance(LMR) devices based on perovskite coatings deposited on planar waveguides. Perovskite thin films have been obtained by means of the spin coating technique and their presence was confirmed by ellipsometry, scanning electron microscopy, and X-ray diffraction testing. The LMRs can be generated in a wide wavelength range and the experimental results agree with the theoretical simulations. Overall, this study highlights the potential of perovskite thin films for the development of novel LMR-based devices that can be used for environmental monitoring, industrial sensing, and gas detection, among other applications.
