This PDF file contains the front matter associated with SPIE Proceedings Volume 9277, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

This paper gives a review for our recent progress on SOI (Silicon-on-insulator)-compatible hybrid nanoplasmonic waveguides which enables a nano-scale light confinement as well as relatively long-distance guided-wave propagation. The strong polarization dependence of silicon hybrid nanoplasmonic waveguides makes it promising to realize on-chip polarization-handling devices with utlrasmall footprints, which is also summarized. Finally, energyefficient thermal-tuning is presented as an example to show the potential of using silicon hybrid nanoplasmonic waveguides as a promising platform to transfer and process both photonic and electronic signals along the same integrated circuit.

Silicon photonics has become a promising technology for photonic integrated circuits. During the past few years, there has been a dramatic increase in the scale and complexity of silicon photonic circuits, which introduces many new design challenges and creates a need for efficient and standardized design flows. We have developed a complete design flow that combines mature electronic design automation (EDA) software with optical simulation software. This flow makes it possible to reliably design, simulate, layout and manufacture large-scale silicon photonic circuits in a unified environment.

Silicon photonics has reached a considerable level of maturity, and the complexity of photonic integrated circuits (PIC) is steadily increasing. As the number of components in a PIC grows, loss management becomes more and more important. Integrated semiconductor optical amplifiers (SOA) will be crucial components in future photonic systems for loss compensation. In addition, there are specific applications, where SOAs can play a key role beyond mere loss compensation, such as modulated reflective SOAs in carrier distributed passive optical networks or optical gates in packet switching. It is, therefore, highly desirable to find a generic integration platform that includes the possibility of integrating SOAs on silicon. Various methods are currently being developed to integrate light emitters on silicon-on-insulator (SOI) waveguide circuits. Many of them use III-V materials for the hybrid integration on SOI. Various types of lasers have been demonstrated by several groups around the globe. In some of the integration approaches, SOAs can be implemented using essentially the same technology as for lasers. In this paper we will focus on SOA devices based on a hybrid integration approach where III-V material is bonded on SOI and a vertical optical mode transfer is used to couple light between SOI waveguides and guides formed in bonded III-V semiconductor layers. In contrast to evanescent coupling schemes, this mode transfer allows for a higher confinement factor in the gain material and thus for efficient light amplification over short propagation distances. We will outline the fabrication process of our hybrid components and present some of the most interesting results from a fabricated and packaged hybrid SOA.

A novel ultra-compact high-efficiency broadband mode converter between silicon (Si) nanowire and silicon slot waveguide based on Silicon-on-Insulator (SOI) is proposed in this paper. By introducing a gradual-width structure between Si nanowire and slot waveguide, the favorable transition between nanowire mode (Gaussian-like mode) and slot mode (non-Gaussian-like mode) can be obtained and then the coupling efficiency is improved. The structure is simulated and optimized by using the three-dimension Finite-Difference Time-Domain Method (3D-FDTD). The coupling efficiency of over 90% within bandwidth of over 600nm can be achieved by only 200nm-length converter which is the smallest size to our knowledge. This presented mode converter can meet the demand of ultra-compact, wavelength-insensitive of monolithic integration.

A novel hollow-core (HW) Y-branch waveguide splitter based on high-contrast grating (HCG) is presented. We calculated and designed the HCG-HW splitter using Rigorous Coupled Wave Analysis (RCWA). Finite-different timedomain (FDTD) simulation shows that the splitter has a broad bandwidth and the branching loss is as low as 0.23 dB. Fabrication is accomplished with standard Silicon-On-Insulator (SOI) process. The experimental measurement results indicate its good performance on beam splitting near the central wavelength λ = 1550 nm with a total insertion loss of 7.0 dB.

We experimentally and theoretically investigate GeSi-based photonics for future on-chip optical interconnect on bulk Silicon substrates with dense wavelength division multiplexing (WDM) system. We experimentally show that Ge-rich Si_1-xGe_x can be used as both a passive low loss waveguide and a substrate to facilitate low-temperature epitaxial growth of Ge-based active devices working at low optical loss wavelength of Ge-rich Si_1-xGe_x waveguides. We also theoretically discussed the possibilities to realize a compact passive component based on Ge-rich Si_1-xGe_x material system on bulk Si wafer. From simulation the system based on Ge-rich Si_1-xGe_x waveguide and the Si_1-yGe_y (y < x) lower cladding layer is good enough to ensure compactness of important on-chip photonic components including passive waveguide and GeSi-based array waveguide grating (AWG). The small refractive index contrast between Ge-rich Si_1-xGe_x waveguide and the Si_1-yGe_y lower cladding layer potentially avoid the polarization dependent loss and detrimental fabrication tolerance of WDM system. Our studies show that GeSi-based photonics could uniquely provide both passive and active functionalities for dense WDM system.

We show that the photonic crystal waveguide and cavity system could be a superior platform to observe and manipulate nonlinear Fano resonance. Using a modified Fano-Anderson model, we can study the nonlinear dynamics in this system. By adding a scattering channel as a continuum to this system, there are bound states in the continuum in such photonic system. We can therefore obtain the tunable interaction of Fano resonances in the Mach-Zehnder-Fano interferometers by exciting the bound state like mode. The nonlinear version of Mach-Zehnder-Fano interferometers can be used to enhance the nonlinear response which facilitates the reduction of optical switching power. In contrast, by adding a scattering channel as a discrete state to this system, we can shape the asymmetry nonlinear transmission of the system. Furthermore, the nonreciprocity of the photonic system can be manipulated dynamically. The unidirectional transmission can be managed by the properties of the input signal, resembling an optical diode with reconfigurable forward direction and transmission contrast. We also address the possibility to control the properties of the nonreciprocity by using a pump pulse, providing a chance to control the system in an all-optical manner.

Observation of photonic spin Hall effect (SHE) manifested by spin-dependent splitting of light in a dielectric-based birefringent metasurface is reported experimentally. By designing the metasurface with homogeneous phase retardation but space-variant optical axis directions, we govern the photonic SHE via space-variant Pancharatnam-Berry phase originated from the local polarization manipulation of the metasurface, essentially, the spin-orbit interaction between the light and the metasurface. Modulating the polarization distribution of the incident light and/or the structure geometry of the metasurface, the photonic SHE could be tunable. This type of metasurface offers an effective way to manipulate the spin-polarized photons and a route for spin-controlled nanophotonic applications.

Despite their name polariton lasers do not rely on stimulated emission of cavity photons. The less stringent threshold conditions are the cause that bosonic polariton lasers can outperform standard lasers in terms of their threshold currents. The part-light and part-matter quasiparticles called polaritons, can undergo a condensation process into a common energy state. The radiated light from such a system shares many similarities with the light emitted from a conventional photon laser, even though the decay of the polaritons out of the finite lifetime cavity is a spontaneous process. We discuss properties of polariton condensates in GaAs based microcavities. The system’s response to an external magnetic field is used as a reliable tool to distinguish between polariton laser and conventional photon laser. In particular, we will discuss the realization of an electrically pumped polariton laser, which manifests a major step towards the exploitation of polaritonic devices in the real world.

Conventional photonic integration technologies are inevitably substrate-dependent, as different substrate platforms stipulate vastly different device fabrication methods and processing compatibility requirements. Here we capitalize on the unique monolithic integration capacity of composition-engineered non-silicate glass materials (amorphous chalcogenides and transition metal oxides) to enable multifunctional, multi-layer photonic integration on virtually any technically important substrate platforms. We show that high-index glass film deposition and device fabrication can be performed at low temperatures (< 250 °C) without compromising their low loss characteristics, and is thus fully compatible with monolithic integration on a broad range of substrates including semiconductors, plastics, textiles, and metals. Application of the technology is highlighted through three examples: demonstration of high-performance mid-IR photonic sensors on fluoride crystals, direct fabrication of photonic structures on graphene, and 3-D photonic integration on flexible plastic substrates.

We propose the fluorescent nanoparticle manipulations at nano-metal structures with floating AC-DEP force for plasmonic applications. The electrode gap was optimized to induce enough DEP force around the nano-structure for manipulation of the nanoparticles. 10um wide gap of electrode was acquired to apply the floating AC-DEP force at various designed metal nano-structure such as nanowire, y-branch and vortex. The all shape of nano-metal structures are formed at the gap of microelectrode and not connected with microelectrode. The gold nano-structures in the gap of microelectrode were fabricated with e-beam lithography and lift-off process. Before the formation of metal nanostructure, micro electrodes for applying the electric field around the metal nano-structures were fabricated with photolithography and lift-off process. Cadmium selenide (CdSe/ZnS) QDs (0.8 nM, emission wavelength of 605 nm) with a 25 nm zinc sulfide capping layer and 100nm polystyrene nano bead (1 nM, emission wavelength of 610nm) were used as fluorescent nanoparticles. We applied the 8 V_pp, 3 MHz sine wave for the positive DEP force, and it resulted in 10⁸ V/m electric field and 10¹¹ V/m electric field gradient around gold nanowire with floating AC. The fluorescent nanoparticle’s attachment at the nanowire is confirmed by the fluorescent optical analysis. The fluorescent nanoparticles are located successfully at designed metal nano-structures for plasmonic applications.

In recent years, haze has become a new type of environmental disaster, it is also one of the most disturbance factors in remote sensing image. Now, to study the influence of haze on electromagnetic waves has got more and more attention. In this paper, the definition of haze and composition of PM_2.5 particles were introduced. And based on Mie scattering theory, the extinction characteristics of single and mixture of PM_2.5 particles with different size and refractive index were analyzed. The calculation shows that the extinction efficiency factor of single PM_2.5 particle changes with the different particle size and refractive index, the oscillation of extinction curves become obvious with different particle size in the case of weak absorption, when it is strong absorption, this phenomenon will disappear. At the same time, based on the study of extinction efficiency factor for single particle and the equivalent method, it is found that the extinction efficiency factor of a lot of particles increase rapidly with the change of particle sizes, then, it will decrease and tend to a constant. The factor is also associated with the change of the width of particle size distribution and refractive index, usually not monotonous. For external mixture of particles, the extinction curve also relates to the mixing ration for the mixing particles. Because there are many mixture of particles in reality, the study of characteristics of extinction efficiency factor in this paper is significant for the research on the optical characteristics of PM_2.5 particles in practice.

Based no the classical spiraling photon model proposed by Hongrui Li, the laws of reflection, refraction of a single photon can be derived. Moreover, the polarization, total reflection, evanescent wave and Goos-Hanchen shift of a single photon can be elucidated. However, this photon model is still unfinished. Especially, the spiraling diameter of a photon is not definite. In this paper, the continuous research works on this new theory are reported. According to the facts that the diffraction limit of light and the smallest diameter of the focal spot of lenses are all equal to the wavelength λ of the light, we can get that the spiraling diameter of a photon equals to the wavelength λ, so we gain that the angle between the linear velocity of the spiraling photon υ and the component of the linear velocity in the forward direction υ_b is 45°, and the energy of a classical spiraling photon E = (1/2)mυ² = (1/2)m2c² = mc². This coincides with Einstein’s mass-energy relation. While it is obtained that the velocity of the evanescent wave in the vacuum is slower than the velocity of light in glass in straight line. In such a way, the optical fiber can slow the light down. In addition, the force analysis of a single photon in optical tweezers system is discussed. And the reason that the laser beam can capture the particle slightly downstream from the focal point can be explained.

In this paper, a novel electro-absorption modulation mechanism based on coupled-quantum-wells (CQWs) is proposed and demonstrated. Compared to a quantum-confined-stark-effect (QCSE) modulator with multiple fully decoupled single-QWs, the newly designed CQW modulator has two sub-quantum-wells partially coupled with a small barrier in between. Modulation is based on the change of electron and hole wave-function overlap in the CQWs, which requires a small bias electric field of <10 kV/cm) compared to the operation of a typical QCSE modulator which requires >50 kV/cm bias electrical field. Theoretically, the power consumption of this new CQW modulator can be lower than 20 fJ/bit and the speed can be higher than 10 Gbps, which outperforms the best Ge/SiGe QCSE modulator that has been previously demonstrated. A proof-of-concept Ge/SiGe CQW modulator based on this novel modulation mechanism was designed and fabricated. Instead of a traditional PIN diode structure, the new CQW modulator uses a PIP structure.

As the numerical aperture (NA) increasing and process factor k₁ decreasing in 193nm immersion lithography, polarization aberration (PA) of projection optics leads to image quality degradation seriously. Therefore, this work proposes a new scheme for compensating polarization aberration. By simulating we found that adjusting the illumination source partial coherent factors σ_out is an effective method for decreasing the PA induced pattern critical dimension (CD) error while keeping placement error (PE) within an acceptable range. Our simulation results reveal that the proposed method can effectively compensate large PA in actual optics.

Epitaxial growth of III-V compound semiconductors on Si has attracted significant attention for many years due to the potential for monolithic integration of III-V based optoelectronic devices with Si integrated circuits. There are three major problems for GaAs monolithic epitaxy on Si, respectively the large lattice mismatch, the difference in thermal expansion coefficient, and growth of a polar material on a nonpolar substrate. Various dislocation reduction techniques have been proposed, such as graded SiGe buffer layers, thermal cycles annealing (TCA), and strained-layer superlattices (SLs) as dislocation filters. Unfortunately, these methods generally require relatively thick epitaxial layers and/or complex epitaxial process. This study relates to the heteroepitaxy of GaAs on nanopatterned Si substrates using the selective aspect ratio trapping method. The dislocations originally generated at the GaAs/Si interface are mostly isolated by the SiO₂ side wall. High-quality GaAs nanowires have been grown on Si(001) substrates by metal-organic chemical vapor deposition. A method of two-step epitaxy of GaAs is performed to achieve a high-quality GaAs layer with a 217 arcsec narrow FWHM of HRXRD. Material quality was confirmed by Scanning electron microscope (SEM) and transmission electron microscopy (TEM). We also simulated the distribution of the light field on the nanoscale GaAs layer surround by Ag films used the FDTD method. The light field confined well in the 250nm width GaAs nanowire which can be used in the nanolasers on Silicon as light sources.

This paper reports ex-situ preparation of conductive polymer/single-walled carbon nanotubes (SWNTs) nanocomposites by adding high conductive SWNTs to the polymer matrix. Sonication methods were used to disperse the SWNTs in the polymer. The conductivity of the nanocomposites is tuned by increasing the concentration of SWNTs. Furthermore, we present two-photon polymerization (2PP) method to fabricate structures on the basis of conductive photosensitive composites. The conductive structures were successfully generated by means of 2PP effect induced by a femtosecond laser.

Generally, nano-scale patterned sapphire substrate (NPSS) has better performance than micro-scale patterned sapphire substrate (MPSS) in improving the light extraction efficiency of LEDs. Laser interference lithography (LIL) is one of the powerful fabrication methods for periodic nanostructures without photo-masks for different designs. However, Lloyd’s mirror LIL system has the disadvantage that fabricated patterns are inevitably distorted, especially for large-area twodimensional (2D) periodic nanostructures. Herein, we introduce two-beam LIL system to fabricate consistent large-area NPSS. Quantitative analysis and characterization indicate that the high uniformity of the photoresist arrays is achieved. Through the combination of dry etching and wet etching techniques, the well-defined NPSS with period of 460 nm were prepared on the whole sapphire substrate. The deviation is 4.34% for the bottom width of the triangle truncated pyramid arrays on the whole 2-inch sapphire substrate, which is suitable for the application in industrial production of NPSS.

State-of-the-art III-V cells have reached the highest energy conversion efficiency among all types of solar cells. However, these cells are not applicable to widespread terrestrial solar energy system yet due to the high cost of epitaxial growth. Ultra-thin film absorbers with advanced light management is one of the most promising solutions to drive down the cost. In this paper, we present an ultra-thin film nano-window gallium arsenide (GaAs) solar cell design. This ultrathin cell consists of a nano-structured Al_0.8Ga_0.2As window layer on the front side to reduce the reflection and to trap the light, and a metal reflector on the back side to further increase the light path. The 300 nm thick GaAs cell with Al_0.8Ga_0.2As nano-window shows a broad band absorption enhancement from visible to near infrared (NIR), achieving a spectrally averaged absorption of 94% under normal incidence. In addition, this cell shows excellent angular absorption properties, achieving over 85% spectral averaged absorption at up to 60 degree off normal incidence. Meanwhile, this structure with planar junction and nano-window has solved the issue of low fill factor and low open-circuit voltage in nano-structured GaAs solar cell. A nano-window cell with a 3 μm thick GaAs junction demonstrated an open circuit voltage of 0.9V.

Semiconductor nanostructures have generated tremendous scientific interests as well as practical applications stemming from the engineering of low dimensional physics phenomena. Unlike 0D and 1D nanostructures, such as quantum dots and nanowires, respectively, 2D structures, such as nanomembranes, are unrivalled in their scalability for high yield manufacture and are less challenging in handling with the current transfer techniques. Furthermore, due to their planar geometry, nanomembranes are compatible with the current complementary metal oxide semiconductor (CMOS) technology. Due to these superior characteristics, there are currently different techniques in exfoliating nanomembranes with different crystallinities, thicknesses and compositions. In this work we demonstrate a new facile technique of exfoliating gallium nitride (GaN) nanomembranes with novel features, namely with the non-radiative cores of their threading-dislocations (TDs) being etched away. The exfoliation process is based on engineering the gallium vacancy (V_Ga) density during the GaN epitaxial growth with subsequent preferential etching. Based on scanning and transmission electron microscopies, as well as micro-photoluminescence measurements, a model is proposed to uncover the physical processes underlying the formation of the nanomembranes. Raman measurements are also performed to reveal the internal strain within the nanomembranes. After transferring these freely suspended 25 nm thin GaN nanomembranes to other substrates, we demonstrate the temperature dependence of their bandgap by photoluminescence technique, in order to shed light on the internal carrier dynamics.

Fluorescence correlation spectroscopy (FCS), a powerful tool to resolve local properties, dynamical process of molecules, rotational and translational diffusion motions, relies on the fluctuations of florescence observables in the observation volume. In the case of rare transition events or small dynamical fluctuations, FCS requires few molecules or even single molecules in the observation volume at a time to minimize the background signals. Metal nanoparticle which possess unique localized surface plasmon resonance (LSPR) have been used to reduce the observation volume down to sub-diffraction limited scale while maintain at high analyst concentration up to tens of micromolar. Nevertheless, the applications of functionalized nanoparticles in living cell are limited due to the continuous diffusion after cell uptake, which makes it difficult to target the region of interests in the cell. In this work, we demonstrate the use of silver nanowires for remote excitation FCS on fluorescent molecules in solution. By using propagation surface plasmon polaritons (SPPs) which supported by the silver nanowire to excite the fluorescence, both illumination and observation volume can be reduced simultaneously. In such a way, less perturbation is induced to the target region, and this will broaden the application scope of silver nanowire as tip in single cell endoscopy.

In this paper we evidenced a broadband transmission from middle infrared to radio spectrum and a band-pass transmission in far infrared based on a sandwich grating structure, which consists a dielectric grating and two metallic covering layers on the top and bottom side of it. It indicates that broadband polarizer or band-pass filter can be inspired from the structure. As a polarizer, the extinction ratio is about 50dB in middle infrared which increases as the wavelength increases; over 90% transmittance for TM polarized light can be maintained from middle infrared to radio spectrum, which doesn’t degrade for incident angle from 0° to 60° . As a band-pass filter working in far infrared region, the resonant transmission peak can be tuned by either varying the thicknesses of the dielectric grating layer or of the metallic coverings. When the resonant transmission peak is tuned from shorter to longer wavelength by increasing the thickness of dielectric grating, the peak transmittance is increased from 61% to 93%, with full width at half maximum (FWHM) bandwidth increases from 13% to 20%. Besides, in order to achieve high peak transmission, the thickness of metallic coverings should be optimized. In consideration of physical mechanism, the step-boosted characteristic of broadband transmission is contributed by the first-order Fabry-Perot (FP)-like cavity resonance supported in the dielectric grating layer along the horizontal direction, while the band-pass transmission is a hybridization resonant mode of the first order FP-like cavity resonance along the horizontal direction and the first-order FP-like cavity resonance along the vertical direction supported in the dielectric grating layer.

The reflection efficiency of material surface can be reduced by fabricated sub-micron periodic structures. Part of the light energy will propagate along the surface of the material as guided wave, thereby, the interaction between material and light is increased and the light absorption efficiency in visible light stealth material is improved. In this paper, two-dimensional (2D) relief periodic structure with 300nm was fabricated by holographic lithography. Test results show that the reflection efficiency of the material surface can be reduce after fabricated 2D periodic structures. However, because of the presence of diffraction orders, the zero order transmission diffraction efficiency is reduced in short wavelength band. Through rational design of the duty cycle and etching depth, the diffraction efficiency of reflection can be reduced, and then, the optical coupling efficiency of the material can be improved and the visible light stealth properties of the material can be improved too.

A compact polarization beam splitter (PBS) based on a microring resonator is proposed and demonstrated numerically by utilizing the full vectorial mode-matching (FVMM) theory and the coupled mode theory (CMT), which are introduced in the aspects of the width of waveguide, the height of waveguide, the radius of microring, and coupling coefficient, etc. Simultaneously, the finite difference time-domain (FDTD) method, a powerful and accurate method for finite size structure, is chosen to simulate and design this PBS. When TE and TM polarized light at 1.55μm are launched into the input port simultaneously, the resonator will drop TM polarized light to the drop port and transmit TE polarized light to the through port. In this way, two orthogonal polarization states are split and transferred to different output ports. The extinction ratio in the order of 10dB is achieved initially based on our recent work. The initial experimental results are also given, which includes three microring resonator with the radius of 15μm, 10μm, and 5μm, respectively. The proposed PBS structure could be utilized to develop ultracompact optical polarization modulating device for large-scale photonic integration and optical information processing.

The optical properties of gold semi-shell nanopartilces with different shell thicknesses, geometrical morphology and physical parameters are theoretically studied by discrete dipole approximation method. The numerical results show that the extinction resonance wavelength of semi-shell nanoparticle is first blue-shifted and then red-shifted as the shell thickness increases, the shell thickness corresponding to resonance wavelength shifting to opposite direction increases with the increase of aspect ratio, and with the increase of dielectric constants of the inner core material and the embedding medium. The shift of the resonance wavelength is ascribed to the mutual interactions between plasmon hybridization and phase retardation. The plasmon hybridization plays an important role as the shell thickness is thin, as the shell thickness get thicker, phase retardation effect will become significant.

A tunable dual-band infrared polarization filter has been proposed and investigated in this paper. Based on the perfect absorption characteristic of the metal-dielectric-metal sandwich structure, the reflection spectrum shows filter performance. This filter consists of three layers. The top layer is a compound metal nano-structure array composing of an asymmetrical cross resonator and a rectangle strip. The middle and bottom layer are dielectric spacer and metal film, respectively. The calculated results show that the filter property is closely related to the polarization of incident light. When the light polarization parallels to the long direction of the rectangle strip, two resonant wavelengths (1310nm and 2000nm) are filtered, and in contrast only one resonant wavelength (1516nm) is filtered when light polarization vertical to it. Moreover, we found that the resonant wavelength is strongly depended on the length of the rectangle strip which caused the resonant effect. Therefore, the filter wavelength can be tuned freely for different light polarization by adjusting the length of the corresponding rectangle strip. We can change one or two filter wavelengths at a time or change the three filter wavelengths at the same time. In addition, the calculated results show all the intensities at the filter wavelengths are closed to zero, which implies the filter can exhibit good filtering performance.

A novel gold nanorods (GNRs) modified optical fiber localized surface plasmon resonance (LSPR) sensor for biochemical detection is demonstrated. The gold nanorods (GNRs) assembled film as the sensing layer was built on the polyelectrolyte (PE) multilayer modified sidewall of an unclad optical fiber. Poly (allylamine hydrochloride) (PAH)/poly (sodium 4-styrenesulfonate) (PSS) films were formed through layer-by-layer (LbL) assembly. The influence of the thickness of polyelectrolyte films was investigated. Simultaneously, the feasibility of the proposed film coupled nanorods optical fiber LSPR sensor in monitoring a series of concentration sucrose solutions with different refractive index is examined. Results suggest that the compact sensor can perform qualitative and quantitative detection in real-time biomolecular sensing.

Single wall carbon nanotubes (SWCNTs) can be metallic, depending on their chirality. For their nanoscale geometric dimension, SWCNTs can be used as antennas to convert high-frequency electromagnetic radiation such as optical radiation into localized energy and vice versa. However, at optical frequencies, traditional antenna design theory fails for metals behave as strongly coupled plasmas. As a matter of fact, an optical antenna responds to a shorter effective wavelength which depends on the material properties and geometric parameters. In this letter, we derived the relationship of effective wavelength with the wavelength of incident radiation for SWCNTs optical antenna, assuming that the SWCNTs can be described by a free electron gas according to the Drude model. SWCNTs optical antenna holds great promise for increasing solar energy conversion efficiency.

Interactions between different resonance modes in optoelectronic structures may introduce coupled modes that can be utilized to explore special optical functions that cannot be realized by conventional methods. A novel dual band filter based on sub-wavelength metal grating with groove caved in and waveguide layer below is proposed in this paper. The metal grating is caved with a groove in the middle of every metal trip, and a waveguide layer with higher refractive index is placed between the metal grating and glass substrate. Using the finite-difference time-domain (FDTD) method, we research the implied physical mechanism by investigating the transmission spectrum with the changing of the structural parameters and the electromagnetic field distributions at some specific wavelengths, such as peaks and valleys in the transmittance. In our simulation, we chose Ag as the grating material and Drude-Lorentz model is employ to describe the dielectric constant. It is found that the two resonance bands are determined by different structural parameters, which due to different mechanism, FP resonance and waveguide resonance, and we also take the groove cavity mode into account when the standing wave oscillates in the groove and result in the dips between two peaks. Besides, the most notable of these features is that the increase of the grating height doesn’t shift these two resonance wavelength at all, and groove parameters only move the first peak wavelength regularly, which could be an excellent candidate for dual band filter in the telecom wavelengths. Our proposed structure with subwavelength may provide potential applications in optoelectronic devices.

A polymer distributed feedback (DFB) laser was fabricated by two-beam interference from MEH-PPV film on clear glass substrate. A direct-writing technique was reported that achieves large-area 1D DFB polymer lasers. The polymer thin film was exposed to a single-shot illumination of the interference pattern of one UV laser pulse at 355 nm. The direct-writing and the lasing characters of 1D DFB polymer lasers were demonstrated. The results show the lower threshold and full width at half maximum (FWHM) from DFB polymer laser than slab waveguide. The peak position is tuned by changing the period from 340 nm to 350 nm. The results show that the simple and low-cost technique that enables highly reproducible mass fabrication is required for the easy realization and more profound investigation of the polymer lasers based on the DFB configuration.

Silicon and porous silicon based photonic crystals are key aspects of photonic circuits with good compatibility with integrated circuits. Here a brief review is carried out on the fabrication of mid infrared photonic crystals using experimental processes of combining ion beam irradiation and electrochemical anodisation of silicon. Experimental processes have been developed to fabricate high aspect ratio trenches in porous silicon, high aspect ratio silicon pillars, buried channels in porous silicon, and multilevel freestanding silicon wires. These structures have the potential to be used for photonic crystals. Several 2D, quasi-3D and 3D mid infrared photonic crystals in porous silicon and silicon have been designed and fabricated.

We demonstrate uniform and sampled Bragg gratings in silicon-on-insulator ridge waveguides with slab-modulated sidewall corrugations. Coupling coefficient and bandwidth can be precisely controlled by varying the distance between the slab-sidewall corrugations and the ridge. A bandwidth of 3 nm at the center wavelength of 1550 nm for uniform Bragg gratings is achieved for 100 nm slab-sidewall corrugation. Based on this structure, sampled gratings with 0.4 nm bandwidth are proposed. The measured results show good agreement with theoretical analyses.

For given intrinsic losses of a single ring resonator sensor, there exists the maximum sharpness, at the extinction ratio of -6dB. However, the maximum sharpness of a single ring resonator sensor is sensitive for the coupling coefficient. In order to obtain the maximum sharpness, the coupling region of the single rings must have a higher precision of manufacture. To solve this problem, this paper proposed eye-like resonator which is formed by a ring resonator (named inner loop) embedd in the dual-bus-coupled ring resonator (named outer loop). Eye-like resonators can generate the asymmetric Fano-resonance spectra of the drop port, numerical calculation of spectra on the drop port is utilized by the transfer matrix method. As the round trip loss varies, the maximum value of sharpness and the corresponding transmission at the resonant point can be obtained by tuning the phase ratio of the outer loop to the inner loop. The maximum value of sharpness increases with the round trip loss, as the outer loop and inner loop coupling coefficient changing, the maximum value of sharpness of Fano-resonance change slowly in a wide range. As the round trip loss and coupling coefficients of the outer loop and inner loop varies, the corresponding transmission at the resonant point remains almost the same, about -6dB. The sharpness of Fano resonant peak is insensitive for the coupling coefficients, which can reduce the requirements of manufacture of coupling region.

This paper demonstrates an approach to fabricate nano-pillar based on thiol-ene via soft-lithography. The template is anodic aluminum oxygen (AAO) with ordered nano-holes with the diameter of 90nm.The nano-pillar consists of rigid thiol-ene features on an elastic poly(dimethylsiloxane) (PDMS) support. It is capable of patterning both flat and curved substrate. The thiol-ene is a new green UV-curable polymer material, including a number of advantages such as rapid UV-curing in the natural environment, low-cost, high resolution, and regulative performance characteristic. Here, we fabricated a two-layer structure, which included rigid thiol-ene nano-pillar with sub-100nm resolution and soft PDMS substrate. The experiment results show that this approach can be used to fabricate high-resolution features and the thiol-ene is an excellent imprint material. The fabrication technique in this paper is simple, low-cost, high-resolution and easy to high throughput, which has broad application prospects in the preparation of nanostructures.

Layer-by-layer self-assembly ultrathin films continue to be of significant interest among researchers for its broad application in diverse areas. Based on electrostatic attraction between materials with opposite charges, multilayer films of (PSS/Cyt c) ₆, (GNPs/Cyt c) ₅ and (PDDA/DNA) ₆ had been successfully fabricated on the surface of gold chip, respectively. The adsorption process had been followed by in suit spectral surface plasmon resonance (SPR) technique in real time. The experimental results demonstrate that adsorption of materials onto the gold chip can induce a redshift of resonance wavelength and the amount of adsorption can be determined by the change of resonance wavelength. Kinetics studies suggest that adsorption of cytochrome c (Cyt c) or deoxy ribonucleic acid (DNA) obeys Langmuir-isotherm theory, while adsorption of gold nanoparticles (GNPs) obey diffusion-controlled model. These results also indicate that GNPs need more time to reach adsorption equilibrium than Cyt c and DNA, due to a small value of diffusion coefficient.0 increasing with the layer, however, (GNPs/Cyt c) ₅ and (PDDA/DNA) ₆ show a nonlinearly increase. Moreover, through controlling the number of assembled layer, the thickness of multilayer films can be precise designed.

We report tunable color output from a fluorescent dye-doped droplet actuated by electrowetting. The system design, based on a planar electrowetting set-up, is compact and straightforward, with minimal voltage requirements for effective actuation. Fluorescent droplets are sourced from a 1 mM solution of rhodamine 6G in distilled water. Initial contact angle for a dye-doped droplet is 72.1°. At a maximum applied voltage of 20 V, the contact angle decreases to 56.5°. Emission spectra are collected as the droplet fluoresces under UV illumination. Over an electrowetting voltage range of 0 to 20 V, the peak fluorescence wavelength shifts from 568 to 546 nm.