In aims to enhance the electric-field confinement capability of Bloch surface wave (BSW) with low propagation loss, here, we develop a high-performance hybrid BSW waveguide that incorporates a high-index nano-ridge loaded photonic crystal slab with a silicon dielectric nanowire. Leveraging the mode hybridization, a subwavelength mode confinement in conjunction with long-range waveguiding is achievable. Its robust properties against the possible fabrication imperfection for practical implementations and comparisons with similar hybrid waveguide configurations are also discussed to indicate the improved guiding performance of our proposed waveguide. These remarkable optical properties render such waveguide to hold the promise of building numerous high-performance nanophotonic devices.
ere we report a high-sensitive Bloch surface wave sensor by integrating a graphene metasurface and a truncated one dimensional (1D) photonic crystal (PC) multilayer structure. The device is configured to be able to excite BSW mode accompanied with a sharp resonance dip, aiming at greatly enhanced sensing performance of the device structure. The sensing capability of the proposed sensor device is theoretically evaluated by investigating the excited mode properties. The result shows that the graphene metasurface coated Bloch surface wave sensor can reach superior detection sensitivity, thus could offer an obvious promotion for improving the performance of Bloch surface wave based sensing applications.
Here we report a hybrid Bloch surface polariton waveguide by integrating a silicon nano-rib loaded periodic multilayer dielectric structure with a dielectric nanowire at telecommunication wavelength. The hybridization between the Bloch surface mode and dielectric mode is investigated by tuning the key structural parameters of the proposed waveguide. Owing to the existence of the silicon non-rib in close proximity to the dielectric nanowire, the characteristics of the Bloch surface mode can be strongly modified, enabling low-loss light guiding in conjunction with subwavelength mode confinement. Such hybrid configuration demonstrates significant superior light guiding properties over the conventional Bloch surface polaritons and nanowire polaritons, which may open possibilities of the implementation of a variety of high-performance integrated photonic components.
A strip/slot hybrid horizontal silicon nitride slot waveguide is designed to provide an ultraflat and low dispersion. By optimizing the height and width of the structure, an ultraflat and low dispersion of ∼0±7 ps/nm/km over 812 nm wavelength range (from 1137 to 1949 nm) can be achieved. The waveguide with a 20-nm conformal overlayer has chromatic dispersion within ±1 ps/nm/km over 682-nm bandwidth. So the flatness is 0.0015, which is the lowest flatness in near-infrared regime of this kind of waveguide to our knowledge. The influence of the waveguide sidewall to dispersion is also discussed.
To study the relationship between Aerosol Optical Depth (AOD) and concentration of PM2.5(Particulate Matter) basing on CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, 51 samples among the CALIPSO Level 2 aerosol profile data of local region from January to April 2014 are selected. After screening these 51 samples under the decided conditions, such as system stability and the type of the materials, the AODs of the samples are calculated. Then a linear regression model is constructed through Matlab software, in which AOD is independent variable and PM2.5 is dependent variable. All the data are fit by the selected five functions: linear, logarithmic, exponential, power, and quadratic. Experimental results show that the value of correlation coefficient of the quadratic equation model is the best one among the functions. So it is feasible to monitor the concentration of PM2.5 using the AOD calculated from CALIPSO Level 2 data.
Nano-particles and nano-period ripples can be used to form some micro-nano-instruments in microelectronics. In this
paper a femtosecond (fs) pulse laser (148fs, 1KHz, center wavelength=775nm) is used to irradiate on metal surface, then
nano-particles and nano-period ripples can be obtained in the focal scale, the size of which is shorter than the center
wavelength. For describing the formation time and characteristic of nano-particles and nano-period ripples, we have
increased the laser fluence from the threshold of material to a higher value and increased the laser exposure time in fixed
laser fluence on different materials. Experimental results show that nano-particles occur earlier than nano-period ripples.
And as the fs laser pulse number being increased, the periodical nano-ripples is clearer and clearer and the depth of
ripples is deeper and deeper. Finally, permanent ablation will occur in the focal scale basing on the nano-ripples. After
surface plasmon polaritons theory is used, the period of nano-ripples can be explained exactly. This work is the basic
research for micro-nano-instruments by fs laser ablation technique on metal surface.
We report a preliminary experiment result of poling in a femtosecond-laser-treated LiNbO3 (LN) crystal. Because of the precision of the femtosecond laser machine, we can control the width and depth of snicks exactly. Then the high-voltage electric field was operated on +z side of the LN crystal. The visible poling pattern was observed by a microscope and machining parameter influences the electric field distribution in the crystal. This approach does not need expensive masks and the periods of PPLN can be adjusted flexibly. Although the mechanism of core formation is not very clear yet, we believe that it would provide a novel technique of making prototype PPLN and other periodically poled crystals.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.