This PDF file contains the front matter associated with SPIE Proceedings Volume 11440, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists.

A guided-wave surface plasmon resonance based sensor using graphene layer for detect the biomolecules has been analyzed. The use of waveguide layer between the gold film and graphene significantly improves the penetration depth and increases the sensitivity, then graphene layer is used to enhance the adsorption of the biomolecules. The thickness and materials of waveguide layer along with the number of graphene layer have been optimized to achieve the best performance of the sensor in terms of sensitivity. The highest sensitivity with 228.8°/RIU is obtained for visible wavelength with optimized thickness of gold and waveguide layer as 45nm and 10nm respectively while the materials of waveguide layer is chosen as zinc oxide and the optimum number of graphene layers is 2.We believe that this sensor could find potential applications in biological detection.

Photon upconversion with the transformation of low-energy photons to high-energy photons is of significant interest for broad applications in biomedicine for stimulation, sensing, and imaging. Conventional upconversion materials rely on non-linear light-matter interactions, exhibit incidence dependent efficiencies and require high power excitation. Here, we present self-powered, micrometer-scale optoelectronic devices for high-performance near-infrared (~810 nm) to visible (630 nm red or 590 nm yellow) photon upconversion. Thanks to its unique photon–electron conversion process, these thin-film, ultra-miniaturized devices realize fast upconversion that is linearly dependent on incoherent, low-power excitation, with a quantum yield of ~1.5%. Encapsulated, freestanding devices are transferred onto heterogeneous flexible substrates and show desirable biocompatibilities within biological fluids and tissues. Demonstrations of optogenetic stimulation with upconversion devices as implantable light sources have successfully performed in vitro and in vivo scenarios. This approach provides a versatile route to achieve upconversion throughout the entire visible spectral range at lower power and higher efficiency than has previously been possible.

Five kinds of heterofluorenes (silafluorene, oxygafluorene, sulfafluorene, phosphafluorene, carbazole) and 2,5- dihexylbenzene alternative conjugated copolymers have been developed via Suzuki coupling reaction. The successful preparation of the conjugated copolymers opens a door for a new kind of host materials with high triplet state energy as excellent host materials and special optical properties with tremendous potential in the field of organic electronics without the typical defects of polyfluorene.

In this paper, a surface plasmon waveguide structure consisting of annular gap and metal-insulator-metal waveguides is proposed, and its spectral characteristics are analyzed and studied. The results show that this waveguide structure has good performance in narrowband filtering in sub-wavelength band, and the central wavelength of the transmission peak is linearly related to the angle of the annular with notch. The results are of great significance for the application of filtering structures in highly integrated photonic circuits.

The advent of optical waveguides with a unique geometry, where the central part is of low refractive index as compared to the material on the sides, here-after named as a slot(s) guarded by slabs with unique properties of light confinement opened new opportunities for lab-on-chip circuits. Apart from passive dispersion compensator circuits (proposed by us for the first time), active optical circuits have also been designed (by other researchers). In this research we are in a quest to harvest the benefits of Silicon-on-Insulator (SOI) slot optical waveguides in the area of photo-voltaic solar power generation; earlier we have proposed simple and easy to implement periodic/ basic multiple air cladded slot structures. In this research work, we have implemented buried SOI slot optical waveguides; the solar spectrum incarceration with our earlier research work is also being compared. With the advancement in nano-technologies, it is never a problem to implement nanometers wide optical waveguides on the window glass. Where conventional photovoltaic solar cells will be embedded either on all corners of a micro-meter wide region or maybe only on one side. The research will open new avenues for researchers in the field of photovoltaic power generation.

With the development of nanophotonics, a number of diffractive optical lenses are designed and demonstrated experimentally, such as metasurfaces and metalens. This study demonstrates derivation the imaging rule of diffractive optical lens based on geometric optics, which treat light as rays without considering the diffraction. The derived imaging rule is theoretically verified by the Rayleigh-Sommerfeld (RS) diffraction theory to simulate the imaging performance a graphene oxide (GO) ultrathin (~200 nm) flat lens working at the wavelength of 600 nm. The results from diffraction theory based on RS model confirms the imaging rule derived from the geometric optics in the paraxial region. The imaging rule can be generally applied to any diffractive lenses, especially ultrathin flat lenses.

Optical antennas are essential components for integrated photonic circuits (PICs) as they allow the effective coupling of light into/from free space with large optical aperture and therefore small divergence angle. Such a function is especially vital in sensing applications such as LIDAR and Doppler velocimetry where the interaction with free space objects is required. However, the design of a linear grating optical antenna is not a trivial task, as the radiation intensity and angle need to be optimized along the antenna length to achieve the desired radiation pattern. In this work, we proposed and realized an automated design scheme for silicon PIC antennas. Utilizing such a scheme, an optical antenna array with 128 μm by 500 μm optical aperture has been designed and fabricated with 0.18 μm fabrication technology. The antenna has been characterized for its divergence angle and radiation pattern. The obtained data match well with design parameters, showing the viability of such an automated design scheme.

Optical spectral broadening induced by self-phase modulation (SPM) in single CdTe nanowires is measured. A significant spectral broadening of about 10 nm is observed using ps near-infrared (NIR) pulses with coupled peak power of a dozen W. Benefiting from the large effective nonlinearity and refractive index of these nanowires, the necessary propagating length goes down to several hundred μms. A relatively large nonlinear-index coefficient (n₂) more than 1×10-¹⁷ m² /W is obtained from transmission spectra experimentally within measured spectral region, which suggest great possibility for these nanowires in developing ultracompact nonlinear optical devices.

N-type AlGaAs Bragg reflectors (DBRs) are an important part of optoelectronic devic-type AlGaAs Bragg reflectors (DBRs) are an important part of optoelectronic devices such as light-emitting diodes and vertical cavity surface emitting lasers and reducing the series resistance is critical to the performance of the device. In this paper, four kinds of modulation-doped 20-cycle N-type Al_0.5Ga_0.5As/AlAs DBR were grown on N-type GaAs substrate by MOCVD. The white light reflection spectrum measurement results show that the peak wavelength of the epitaxial wafer meets the requirements of red light band. The upper and lower electrodes were prepared for each of the four structures, and the IV characteristics were tested after Cleavaged. The results show that the series resistance of the epitaxial wafer with the AlGaAs layer concentration of 1×10¹⁹ cm^-3 and the AlAs layer doping concentration of 5×10¹⁸ cm^-3 is the smallest. The resistance value was 1.36×10 ^-6 Ω cm ². It shows that the modulation doping method can effectively reduce the series resistance of DBR.

In order to explore the key factors of the SPR effect, such as sensitive material, thickness of sensitive metal film, incident angle and wavelength, especially the affection of the incident light wavelength on the modulated reflectivity, calculations and analyses are carried out in this paper. Simulation results show that Ag has the lowest reflectivity when the incident light with shorter wavelength in visible wave band, Au has the lowest reflectivity with red light, and Cu has the best effect from 600 nm to infrared band. The ranges of thickness measurement for thin films can be obtained when the light source wavelength and incidence angle are fixed with the adopted metal sensitive material. Moreover, there is a special range of incidence angle that can put up a significant SPR effect phenomenon when there are definite metal films and wavelength of incident light.

Subwavelength grating (SWG) structures can greatly improve the design flexibility of silicon photonic integrated circuits. Most SWG structures reported in the literature so far are fabricated with electron beam lithography, limiting their use in mass production. In this work, a study has been carried out for the SWG waveguide and coupling structures that are compatible with 0.18 μm CMOS process. The optical propagation in this SWG waveguide has been analyzed, and the loss of coupling structures between solid silicon waveguide and SWG waveguide have been studied through simulation and measurement. The overall results show a potential of the design and fabrication of SWG waveguides with 0.18 μm CMOS process.

Three-dimensional ordered structure of metal-organic frameworks (MOFs) optical gas sensor was successfully prepared by vertical deposition method. This sensor was built to detect carbon tetrachloride (CCl₄) gas. When exposed to carbon tetrachloride gas, the sensing system can clearly detect the drift of the peak of its reflection spectrum. The gas sensor showed the good characteristics of stability and strong anti-interference ability. Moreover, it was found that the concentration of measuring CCl₄ gas is a linear relationship with the optical signal of the sensitive element. The results of measuring CCl₄ gas demonstrated that the sensor has a high sensitivity for CCl₄ gas with a fast response about 2 second, therefore it takes advantages of high sensitivity and simple structure.

Using the principle of Surface Plasmons Polaritons, we propose a graphene broadband terahertz absorption structure that achieves the tunable absorption of electromagnetic waves. In our absorption structure, the method of patterning graphene is used to realize continuous broadband absorption from 0.5THz to 2.1THz. The absorption which is more than 50% reaches 1.1THZ, especially the structure designed here has three plasmonic resonance peaks which above 98% at 0.79THz, 1.18THz and 1.35THz, respectively. In addition, the symmetry in the pattern design consider that our absorption structure is not sensitive to the polarization and incident angle. Due to a series of excellent characteristics of the absorption structure, it may play an important role in the field of aircraft stealth, absorber, and light wave modulation.

The time-wavelength optical pulse interleaver is an important component of a wavelength-interleaved photonic analog-to- digital converter (ADC). The two important performance indexes of interleavers are power imbalance and delay error. In order to reduce the power imbalance, a runway-shaped and shallow ridge silicon waveguide optical delay line (ODL) array is adopted. The measured average loss of the ODL is only 0.68 dB/cm. By measuring the delay of the ODL array, we optimize the ODL’s length to reduce the interleaver’s delay error. A four-channel interleaver with low loss and small delay error was fabricated on the silicon-on-insulator (SOI) platform, and the power imbalance is 0.9 dB. The root mean square (RMS) delay error is 0.34% and the crosstalk is below -20.3 dB.

Etched diffraction grating (EDG) with Bragg reflectors based demultiplexer offers advantages of low insertion loss, compact size and tolerant process, which has been the focus of a great deal of research. The Bragg reflector, consisting of alternating dielectric layers coupled to a homogeneous medium, is a kind of one-dimensional photonic crystal (1-D PC). This paper proposed a design method based on 1-D PC theory to design Bragg-EDG. With this design method, the reflection condition calculated by the 1-D PC theory can be matched perfectly with the diffraction condition. As a result, the shift of central wavelength of diffraction spectra can be improved, while keeping high diffraction efficiency. With a small number of dielectric layers, a Bragg-EDG with broad bandwidth, good channel uniformity and low next-channel crosstalk level can be obtained. Performances of Bragg-EDG for TE and TM-mode are also investigated, and the result shows that the grating by this method has a small polarization dependent loss. The reflection bandwidth of the TE-mode is greater than that of the TM-mode; while for the diffraction efficiency, TM-mode performs better. An analysis of etching deviation was also carried on to study the effect of fabrication errors on the performance of the grating. Simulation results indicate that the diffraction grating designed by this approach is very tolerant concerning fabrication imperfections, and a 10% deviation of the width of the etched trench does not lead to a significant decrease in reflection and diffraction efficiencies of the grating at designed work band.

In this work, we theoretically investigate the strong coupling of Tamm Plasmon Polaritons (TPP) in a graphene/DBR/Ag hybrid structure. It is found that TPP can be generated at both upper graphene and lower Ag interfaces, which can strongly couple with each other, allowing strong light-matter interaction with dual-band perfect absorption. Numerical results reveal that resonance frequency of hybrid modes can be tuned by adjusting geometry parameters or dynamically modifying graphene Fermi energy. Coupling strength for the TPP hybrid modes exhibits a large tuning range, from large Rabi splitting to a very narrow induced transparency. The tunable TPP strong coupling with a dual-band perfect absorption in this simple layered system is potential in developing a broad range of graphene-based optoelectronic devices.