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We report our in-house R&D efforts of designing and developing key integrated photonic devices and technologies for a chip-scale optical oscillator and/or clock. This would provide precision sources to RF-photonic systems. It could also be the basic building block for a photonic technology to provide positioning, navigation, and timing as well as 5G networks. Recently, optical frequency comb (OFC)-based timing systems have been demonstrated for ultra-precision time transfer. Our goal is to develop a semiconductor-based, integrated photonic chip to reduce the size, weight, and power consumption, and cost of these systems. Our approach is to use a self-referenced interferometric locking circuit to provide short-term stabilization to a micro-resonator-based OFC. For long-term stabilization, we use an epsilon-near-zero (ENZ) metamaterial to design an environment-insensitive cavity/resonator, thereby enabling a chip-scale optical long-holdover clock.

Understanding the near-field electromagnetic interactions that produce optical orbital angular momentum (OAM) is crucial for integrating twisted light into nanotechnology. Here, we examine the cathodoluminescence (CL) of plasmonic vortices carrying OAM generated in spiral nanostructures. The nanospiral geometry defines a photonic local density of states that is sampled by the electron probe in a scanning transmission electron microscope (STEM), thus accessing the optical response of the plasmonic vortex with high spatial and spectral resolution. We map the full spectral dispersion of the plasmonic vortex in spiral structures designed to yield increasing topological charge. Additionally, we fabricate nested nanospirals and demonstrate that OAM from one nanospiral can be coupled to the nested nanospiral, resulting in enhanced luminescence in concentric spirals of like handedness with respect to concentric spirals of opposite handedness. The results illustrate the potential for generating and coupling plasmonic vortices in chiral nanostructures for sensitive detection and manipulation of optical OAM., Tiny spirals make twisted light Nano-sized spiral structures developed by researchers in the US provide an excellent platform to generate and detect light beams carrying angular momentum. This so-called twisted light, with a helical wave shape, could be used to manipulate tiny objects in future devices such as quantum computers. Jordan Hachtel at Oak Ridge National Laboratory, Tennessee and co-workers fabricated ‘nanospirals’ on silver-coated silicon nitride membranes, and bombarded the samples with a high-energy electron beam from a scanning transmission electron microscope (STEM). The beam excites a coupled light-electron surface state called a plasmonic vortex, which emits twisted light. Crucially, the STEM technique can observe the luminescence coming from the vortex with nanoscale spatial resolution across the entire visible-light regime.

To determine the prognostic significance of kinesin superfamily gene (KIF) expression in patients with brain cancer, including low-grade glioma (LGG) and glioblastoma (GBM), we comprehensively analyzed KIFs in 515 LGG and 595 GBM patients. Among KIFs, KIF4A, 9, 18A, and 23 showed significant clinical implications in both LGG and GBM. The mRNA and protein expression levels of KIF4A, 9, 18A, and 23 were significantly increased in LGG and GBM compared with those in the normal control groups. The mRNA expression levels of KIF4A, 9, 18A, and 23 in LGG were significantly increased in the high-histologic-grade group compared with those with a low histologic grade. Genomic analysis showed that the percent of mRNA upregulation of KIF4A, 9, 18A, and 23 was higher than that of other gene alterations, including gene amplification, deep deletion, and missense mutation. In addition, LGG patients with KIF4A, 18A, and 23 gene alterations were significantly associated with a poor prognosis. In survival analysis, the group with high expression of KIF4A, 9, 18A, and 23 mRNA was significantly associated with a poor prognosis in both LGG and GBM patients. Gene Set Enrichment Analysis (GSEA) revealed that high mRNA expression of KIF4A, 18A, and 23 in LGG and GBM patients showed significant positive correlations with the cell cycle, E2F targets, G2M checkpoint, Myc target, and mitotic spindle. By contrast, high mRNA expression of KIF9 in both LGG and GBM patients was significantly negatively correlated with the cell cycle, G2M checkpoint, and mitotic spindle pathway. However, it was significantly positively correlated with EMT and angiogenesis. This study has extended our knowledge of KIF4A, 9, 18A, and 23 in LGG and GBM and shed light on their clinical relevance, which should help to improve the treatment and prognosis of LGG and GBM.

The authors present an experimental demonstration of a fluidic-based plasmonic device for spectral analysis. The demonstrated device is based on the modification of surface plasmon resonance in periodically coupled metallic nanostructures using external refractive index perturbation for spectral analysis. The refractive index perturbation alters the resonance condition of the internal surface plasmon waves and introduces a spectral shift in the transmission band for spectral sampling. In this demonstration, precise control of the centre wavelength of the surface plasmon resonance was achieved by changing the local environment of the nanostructures via microfluidic channels. The fluidic-based approach has a great impact on existing resonance-based spectral analysis devices by offering an efficient way to acquire a very large number of spectral sampling.

A mouse was generated containing a floxed exon 3 of the gene for the kinesin family member KIF9. By in situ hybridization, expression of KIF9 mRNA was highest in the testis and was also strong in epithelia containing multi-ciliated cells such as the ependyma, bronchioles and oviduct. Deletion of the exon led to loss of KIF9 expression at the mRNA and protein level with no effect on viability. However, homozygous KIF9 knockout males were sterile. Although KIF9 knockout sperm were motile, they were unable to fertilize oocytes in an in vitro fertilization assay. Closer examination of sperm motility indicated a subtle difference in waveform. Our results suggest that KIF9 plays a role male fertility, possibly through regulation of flagellar waveforms in ciliated cells.

Background The resistance to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is one of the most important problems in lung cancer field. Mitogen-inducible gene 6 (Mig-6) is known to inhibit the kinase activity of epidermal growth factor receptor (EGFR) and studies of mouse models suggested tumor suppressive function of Mig-6 in lung cancer. On the contrary, the results of clinical studies showed that lung cancer patients with high expression of Mig-6 are associated with a poor prognosis. Recent study showed that unlike wild type (WT) EGFR, mutant EGFR phosphorylates Mig-6 and phosphorylated Mig-6 negatively regulates the degradation of EGFR mutants in lung adenocarcinoma. Here, we tried to untangle the controversies surrounding Mig-6 function in lung cancer and EGFR-TKI resistance. Methods We compared the expression and phosphorylation status of Mig6 in the EGFR-TKI resistant lung adenocarcinoma (PC9/GR cells) to EGFR-TKI sensitive lung adenocarcinoma (PC9 cells). We checked the function of Mig6 by knock down and overexpression in those cells and evaluated the efficacy of combination of Mig6 knock down and EGFR-TKI in PC9/GR. The correlation between Mig6 expression and the prognosis of lung adenocarcinoma were examined by The Cancer Genome Atlas (TCGA) data and clinical samples. Results Our results showed that the expression of Mig-6 was significantly increased PC9/GR cells compared to PC9 cells. And most of Mig-6 was phosphorylated in PC9 and PC9/GR cells. Moreover, overexpression of Mig-6 significantly increased the cell proliferation, invasion and epithelial mesenchymal transition (EMT) in PC9 cells. Combination of Mig-6 knock-down and EGFR-TKI treatment significantly overcame the EGFR-TKI resistance. In addition, our analyses of clinical samples confirmed that high Mig-6 expressions are correlated with a poor prognosis and EGFR-TKI resistance in lung adenocarcinoma. Conclusion Our work supports that Mig-6 is an oncoprotein in the context of EGFR-TKI resistant lung adenocarcinoma. We propose that targeting Mig-6 may be a promising strategy to overcome the EGFR-TKI resistance in lung cancer.

TEA Domain Transcription Factors (TEADs) are important in development and serve essential roles in tumorigenesis; however, the role of TEAD2 expression in hepatocellular carcinoma (HCC) has not been widely examined. The present study was conducted to investigate the expression status of TEAD2 in HCC and to evaluate whether the expression of TEAD2 is associated with the prognosis of patients with HCC. mRNA expression data was retrieved for Hippo pathway genes of 50 normal control and 377 HCC samples from The Cancer Genome Atlas data portal. Gene set enrichment, GeneNeighbors, ClassNeighbors and survival analyses were then performed based on the gene expression levels. The mRNA expression of TEAD2 and VGLL4 was significantly higher in HCC compared with the normal control samples, and the mRNA expression of TEAD2 was higher in advanced stages than in early stages. Specifically, survival analysis revealed that higher mRNA expression of TEAD2 was significantly associated with a less favorable overall survival rate (P=0.0067) and there was a trend towards significance between higher mRNA expression of VGLL4 and poor overall survival rate (P=0.051). According to the gene set enrichment analysis, patients with higher mRNA expression of TEAD2 and VGLL4 had strongly enhanced epithelial‑mesenchymal transition and angiogenesis, which are associated with tumor progression. In conclusion, increased mRNA expression of TEAD2 is associated with a poor prognosis in patients with HCC. TEAD2 may serve as a prognostic factor for HCC and a novel therapeutic target.

Background The resistance of lung cancer to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is one of the unconquered frontiers in chemotherapy. Mitogen-inducible gene 6 (Mig-6) is known to inhibit the kinase activity of epidermal growth factor receptor (EGFR). Similarly, numerous studies of mouse models suggested tumor suppressive function of Mig-6 in lung cancer. On the contrary, the results of clinical investigations revealed that lung cancer patients with elevated expression of Mig-6 are associated with a poor prognosis. More recent work showed that unlike wild type (WT) EGFR, mutant EGFR phosphorylates Mig-6 and phosphorylated Mig-6 negatively regulates the degradation of EGFR mutants in lung adenocarcinoma. Here, we tried to untangle the controversies surrounding Mig-6 function as a protagonist or an antagonist of EGFR-TKI resistant lung cancer. Methods We compared the expression and phosphorylation status of Mig-6 in the EGFR-TKI resistant lung adenocarcinoma (PC9/GR cells) to EGFR-TKI sensitive lung adenocarcinoma (PC9 cells). We investigated the function of Mig-6 by either depletion or overexpression of Mig-6 in those cells and evaluated the efficacy of combining of Mig-6 knock-down and EGFR-TKI treatment in PC9/GR. The correlation between Mig-6 expressions and the prognoses of lung adenocarcinoma was examined by The Cancer Genome Atlas (TCGA) data and clinical samples. Results Our results indicated that the expression of Mig-6 was significantly increased in PC9/GR cells compared to that of PC9 cells. The significant portion of Mig-6 existed as a phosphorylated form in PC9 and PC9/GR cells. Moreover, overexpression of Mig-6 significantly increased the cell proliferation, invasion and epithelial mesenchymal transition (EMT) in PC9 cells. Combination of Mig-6 knock-down and EGFR-TKI treatment significantly overcame the EGFR-TKI resistance of PC9/GR cells. In addition, our analyses of clinical samples confirmed that high Mig-6 expressions positively correlate with a poor prognosis and EGFR-TKI resistance in lung adenocarcinoma. Conclusion Our findings reinforce scientific notion of Mig-6 as an oncoprotein in the context of EGFR-TKI resistant lung adenocarcinoma. We propose that targeting Mig-6 may be a promising strategy to overcome the EGFR-TKI resistance in lung cancer.

Yes-associated protein 1 (YAP1) is a key transcriptional regulator in the Hippo signaling pathway that plays a critical role in the development and progression of several types of malignancies, including ovarian cancer. Herein, we investigated the expression of YAP1 and its clinical significance in a large population of patients with ovarian serous cystadenocarcinoma (OSC), which is the most common form of epithelial ovarian neoplasm, using the TCGA database. Surprisingly, cross-cancer mRNA expression and alterations in YAP1 were higher in OSC than in those of other types of cancers in the TCGA database. YAP1 mRNA expression was significantly higher in OSC compared with normal ovarian samples, and was higher in stages III and IV, than stages I and II. The level of YAP1 protein, which is mainly localized to the nucleus, was also higher in stage IV as compared with stages I, II and III. However, the protein level of pYAP1, which is inactive and is localized to the cytoplasm, was not significantly different between stages. The ratio of pYAP/YAP, which shows higher activity at a low ratio, was lower in stage III than in stages I and II. High YAP and low pYAP levels were significantly correlated with a poor prognosis in patients with OSC. The mRNA and protein expression of YAP1 were significantly increased in the proliferative subtype as compared to the differentiated, immunoreactive and mesenchymal subtypes. According to bioinformatics analysis, YAP1 is most highly correlated with the cell cycle. TGF-β signaling and WNT signaling were significantly increased in the high YAP1 group according to gene set enrichment analysis. Taken together, our results suggest that not only high YAP1 expression but also its subcellular distribution may be associated with poor overall survival in patients with OSC.

Cytochrome P450 family 4 (CYP4) enzymes are known as microsomal omega (ω)-hydroxylases that metabolize fatty acids, eicosanoids, vitamin D and carcinogens. Thus, CYP4 enzymes may influence tumor development and progression. The aim of the present study was to evaluate the CYP4 expression profile in hepatocellular carcinoma (HCC) and its clinical relevance. The present study obtained CYP4 mRNA expression data for 377 HCC cases from The Cancer Genome Atlas cohort and performed Kaplan‑Meier survival, Gene Ontology functional enrichment, and gene set enrichment analysis (GSEA). In addition, the level of CYP4F2 protein expression was evaluated in matched pairs of HCC and non‑tumor tissue samples and the results were correlated with the clinicopathological characteristics of HCC (n=113). HCC survival analyses indicated better overall survival in patients with high CYP4F2, CYP4F12 and CYP4V2 mRNA expression levels; the results for histological grade and Tumor‑Node‑Metastasis stage supported these results. GSEA revealed high levels of CYP4F2, CYP4F12 and CYP4V2 mRNA expression to be negatively correlated with the expression of cell cycle‑associated genes. CYP4F2 protein expression was higher in non‑neoplastic liver tissue than in HCC tissue and positively correlated with favorable pathological tumor stage (I vs. II‑IV; P=0.022) and was a good independent prognostic factor for overall survival (P=0.004). These results demonstrate that the expression levels of the genes CYP4F2, CYP4F12 and CYPV2 are favorable prognostic factors in HCC and suggest the potential predictive diagnostic and prognostic roles of CYP4F2, CYP4F12 and CYPV2 gene expression in HCC.

Yes-associated protein 1 (YAP1) is a transcriptional regulator of the Hippo pathway, which regulates the development and progression of a number of types of cancer, including that of the colon. In the present study, the expression levels of Hippo pathway genes and their clinical significance were investigated in 458 patients with colon adenocarcinoma (COAD), the most frequently diagnosed neoplastic disease globally, using data obtained from The Cancer Genome Atlas database. Notably, mRNA expression of YAP1 was higher in COAD than in other types of gastrointestinal tract cancer. Expression of YAP1 mRNA was higher in COAD than in normal colon samples and was significantly higher in Tumor-Node-Metastasis (TNM) stages III-IV than in stages I-II. YAP1 protein levels, a protein primarily localized in the nucleus, was greater in TNM stages III-IV than in stages I-II. The level of pYAP1, which is inactive and localized in the cytoplasm, was significantly higher in TNM stages III-IV than in stages I-II. However, the YAP1/pYAP1 ratio, which is representative of activity, was higher in TNM stages III-IV than in stages I-II. High mRNA expression of YAP1, TAZ and TEAD4 was associated with a poor prognosis in patients with COAD. Bioinformatics analysis revealed that YAP1 was associated with DNA duplication, cell proliferation and development. Wnt signaling and transforming growth factor-β signaling were significantly higher in the high-YAP1 group, according to data from Gene Set Enrichment Analysis. Taken together, the results indicate that the subcellular distribution of YAP1 and high mRNA expression of YAP1, TAZ and TEAD4 may be associated with poorer overall survival rates in patients with COAD.

Accelerated eutrophication of surface water sources has resulted in an increased presence of cyanobacterial blooms in fresh water. The release of hepatotoxins like microcystins from such blooms can have a catastrophic impact on local human and wildlife ecosystems. Therefore, a rapid, low-cost, reliable, and highly sensitive method for low-concentration detection of microcystins is needed to minimize risks to public health. In this paper, we report the first experimental demonstration of microcystin-leucine-arginine (MC-LR) detection in water at low part-per-trillion levels using a portable optical sensor. The demonstrated biosensor utilizes a highly sensitive electromagnetic surface wave in periodically coupled artificial nanostructures to directly probe the interaction between immobilized antibodies and MC-LR. The surface customization reported here uses a layer-by-layer polyelectrolyte adsorption process to provide highly stable and site-directed immobilization of target antibodies. Steady-state analysis of the sensor's response confirms that the plasmonic sensor can detect the presence of MC-LR antigens at part-per-trillion levels. The demonstrated sensor is an important first step toward realizing a lab-on-a-chip sensing system for in situ, autonomous, real-time, distributed environmental monitoring of MC levels in drinking water.

To determine the prognostic significance of kinesin superfamily gene (KIF) expression in patients with brain cancer, including low-grade glioma (LGG) and glioblastoma multiforme (GBM), we comprehensively analyzed KIFs in 515 LGG and 595 GBM patients. Among KIFs, KIF4A, 9, 18A, and 23 showed significant clinical implications in both LGG and GBM. The mRNA and protein expression levels of KIF4A, 9, 18A, and 23 were significantly increased in LGG and GBM compared with those in the normal control groups. The mRNA expression levels of KIF4A, 9, 18A, and 23 in LGG were significantly increased in the high-histologic-grade group compared with those with a low histologic grade. Genomic analysis showed that the percent of mRNA upregulation of KIF4, 9, 18A, and 23 was higher than that of other gene alterations, including gene amplification, deep deletion, and missense mutation. In addition, LGG patients with KIF4A, 18A, and 23 gene alterations were significantly associated with a poor prognosis. In survival analysis, the group with high expression of KIF4A, 9, 18A, and 23 mRNA was significantly associated with a poor prognosis in both LGG and GBM patients. Gene Set Enrichment Analysis (GSEA) revealed that high mRNA expression of KIF4A, 18A, and 23 in LGG and GBM patients showed significant positive correlations with the cell cycle, E2F targets, G2M checkpoint, Myc target, and mitotic spindle. By contrast, high mRNA expression of KIF9 in both LGG and GBM patients was significantly negatively correlated with the cell cycle, G2M checkpoint, and mitotic spindle pathway. However, it was significantly positively correlated with EMT and angiogenesis. This study has extended our knowledge of KIF4A, 9, 18A, and 23 in LGG and GBM and shed light on their clinical relevance, which should help to improve the treatment and prognosis of LGG and GBM. Citation Format: SangYeon Cho, DongWoon Kim. Integrative analysis of KIF4A, 9, 18A, and 23 and their clinical significance in low-grade glioma and glioblastoma multiforme [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5245.

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex-derived reactive oxygen species (ROS) promote chronic liver inflammation and remodeling that can drive hepatocellular carcinoma development. The role of NOX expression in hepatocellular carcinoma (HCC) has been partially investigated; however, the clinical relevance of collective or individual NOX family member expression for HCC survival remains unclear. Here, we obtained NOX mRNA expression data for 377 HCC samples and 21 normal liver controls from the TCGA data portal and performed Kaplan-Meier survival, gene ontology functional enrichment, and gene set enrichment analyses. Although most NOX genes exhibited little change, some were significantly induced in HCC compared to that in normal controls. In addition, HCC survival analyses indicated better overall survival in patients with high NOX4 and DUOX1 expression, whereas patients with high NOX1/2/5 expression showed poor prognoses. Gene-neighbour and gene set enrichment analyses revealed that NOX1/2/5 were strongly correlated with genes associated with cancer cell survival and metastasis, whereas increased NOX4 and DUOX1 expression was associated with genes that inhibit tumour progression. On the basis of these data, NOX family gene expression analysis could be a predictor of survival and identify putative therapeutic targets in HCC.

Even though the primo vascular system (PVS) has been observed in large caliber lymph vessels by several independent teams, the presence of the PVS in the thoracic duct has been reported by only one team, probably because reproducing the experiment is technically difficult. This brief report presents a new, relatively straightforward method, which is a simple modification of the previous method of dye injection into the lumbar node, to observe the PVS in a thoracic duct of a rat by injecting Alcian blue into the renal node. When this new method was applied to a rat, the branching of the primo vessel in the thoracic duct was clearly displayed. Thus, this new method is expected to extend the network of the PVS from abdominal lymph ducts to thoracic ones.

Peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) is a key modulator of mitochondrial biogenesis. It is a coactivator of multiple transcription factors and regulates metabolic processes. However, little is known about the expression and function of PGC1α in glioblastoma multiforme (GBM), the most prevalent and invasive type of brain tumor. The purpose of the present study was to investigate the biological function, localization and expression of PGC1α in GBM. It was observed that PGC1α expression is increased in the tumor cells, and a higher level of expression was observed in the mitochondria. Bioinformatics analyses identified that metabolic and mitochondrial genes were highly expressed in GBM cells, with a high PGC1α mRNA expression. Notably, mitochondrial function-associated genes were highly expressed in cells alongside high PGC1α expression. Collectively, the results of the present study indicate that PGC1α is associated with mitochondrial dysfunction in GBM and may have a role in tumor pathogenesis and progression.

The revolution in integrated circuits over the past 50 yr has produced inexpensive computing and communications systems that are powerful and portable. The technologies for these integrated chip-scale sensing systems, which will be miniature, lightweight, and portable, are emerging with the integration of sensors with electronics, optical systems, micromachines, microfluidics, and the integration of chemical and biological materials (soft/wet material integration with traditional dry/hard semiconductor materials). Hence, we stand at a threshold for health monitoring technology that promises to provide wearable biochemical sensing systems that are comfortable, inauspicious, wireless, and battery-operated, yet that continuously monitor health status, and can transmit compressed data signals at regular intervals, or alarm conditions immediately. In this paper, we explore recent results in chip-scale sensor integration technology for health monitoring. The development of inexpensive chip-scale biochemical optical sensors, such as microresonators, that are customizable for high sensitivity coupled with rapid prototyping will be discussed. Ground-breaking work in the integration of chip-scale optical systems to support these optical sensors will be highlighted, and the development of inexpensive Si complementary metal-oxide semiconductor circuitry (which makes up the vast majority of computational systems today) for signal processing and wireless communication with local receivers that lie directly on the chip-scale sensor head itself will be examined.

We present the design, fabrication, and experimental characterization of a nanoslit-based metasurface that offers polarization-selective optical transmission for advanced imaging applications. The metasurface consists of an array of meta-atoms, constructed with two orthogonally coupled subwavelength apertures. Highly enhanced optical transmission was achieved by selective excitation of surface plasmon waves on the metasurface. By rotating the orientation of the linearly polarized incident beam, switching of enhanced optical transmission bands through the metasurface was experimentally demonstrated. This demonstration is a significant step towards developing advanced multispectral imaging devices.

The performance of three optoelectronic structures incorporating substrate-embedded InP-based inverted metal-semiconductor-metal photodetectors and/or volume holographic gratings are analyzed and compared at the primary optical communication wavelengths. These structures, in conjunction with optical-quality polymer layers, can be easily integrated into silicon microelectronic substrates for the purpose of implementing potentially low-cost high-data-rate chip-level or substrate-level optical interconnects. The structures are as follows: a) an evanescent-coupling architecture with a substrate-embedded photodetector, b) a volume-holographic-grating coupler architecture with a substrate-embedded photodetector, and c) a volume-holographic-grating coupler architecture with a flip-chip-bonded photodetector. It is found that the primary characteristic of the evanescent coupling architectures is the efficient performance for both TE and TM polarizations with the disadvantage of exponentially decreasing efficiency with increasing separation between the waveguide film layer and the photodetector layer. On the other hand, the primary characteristic of the volume holographic grating architectures is the possibility of wavelength and polarization selectivity and their independence on the separation between the photodetector layer and the waveguide. Comparison of the analysis with experimental results is also included in the case of the evanescent coupling into a substrate-embedded photodetector.

Significant opportunities exist for optical interconnections at the board, module, and chip level if compact, low-loss, high-data-rate optical interconnections can be integrated into these electrical interconnection systems. To create such an integrated optoelectronic/electronic microsystem, mask-based alignment of the optical interconnection waveguide, optoelectronic active devices, and interface circuits is attractive from a packaging alignment standpoint. This paper describes an integration process for creating optical interconnections which can be integrated in a postprocessing format onto standard boards, modules, and integrated circuits. These optical interconnections utilize active thin-film optoelectronic components embedded in the waveguide/interconnection substrate, thus eliminating the need for optical beam turning elements and their alignment, and providing an electrical output on the substrate from an optical interconnection. These embedded optical interconnections are reported herein using BCB polymer optical waveguides with embedded InGaAs-based thin-film inverted metal-semiconductor-metal (I-MSM) photodetectors on an Si substrate. These interconnections have been fabricated and tested, and the coupled optical signal from the waveguide to the embedded photodetector was theoretically modeled at 56.4%, which was supported by an experimental estimate of 47.8%. The measured full-width at half maximum of the electrical pulse from the MSM photodetector embedded in the waveguide was 16.73 ps for an input 500-fs optical laser pulse.

Combustion instability accompanied with low-frequency oscillations is one of the typical phenomena in a ducted flame burner. This is due to the interaction between unsteady heat release and the sound pressure field known as thermoacoustic feedback. A parametric study was carried out through measurements of acoustic pressure and flame radiation at various conditions not only to elucidate the effect of Reynolds number and equivalence ratio on thermoacoustic oscillation, but also to understand the mechanism of the onset of thermoacoustic resonance in a ducted flame burner. The results explain that equivalence ratio has significant effects on the magnitude of pressure and heat fluctuation as well as the fundamental frequency. It is also found that the onset of thermoacoustic resonance is strongly affected by the interacting mechanism between acoustic energy and heat release.

We present the first experimental demonstration of label-free malaria pathogen detection in whole blood lysate using plasmon nanostructures. Previous studies on plasmonic biosensing have measured antibody-antigen binding, proteinprotein interactions, and detection of bacteria. However, unlike our sensor, many of these works rely on complex optical setups to excite surface plasmon waves. The demonstrated plasmon sensor is a compact, highly sensitive, cost effective, selective diagnostic tool for many portable biosensing applications such as point-of-care diagnostics. To achieve malaria pathogen detection, we utilized a highly site-directed and stable antibody immobilization process on the nanostructure's surface. The measured refractive index sensitivity of the nanostructured sensor is 378 nm/RIU in the visible range.

We present modeling and simulation results on a new family of waveguided interferometric 2 x 2 optical routing switches actuated by electro-optic or thermo-optic or all-optical control. Two pairs of coupled microring resonators provide two 3dB coupling regions within a compact Mach-Zehnder geometry. An index perturbation (delta)n of 2 x 10(-3) is sufficient to produce 100% 2 x 2 switching. This perturbation can be applied to one arm of the MZI or to the four rings in the device or to an additional ring that is coupled to one arm. We find that push-pull control is effective for switching: for example, when carriers are injected in one region and depleted in a corresponding second region. An optical transfer-matrix technique is employed to determine the electromagnetic response (the 1550-nm switching characteristics) of the three device-types. Microdisks can be employed instead of microrings, if desired.

We report on the characterization of long-range surface plasmon waveguide bends at telecom wavelengths (lambda=1550 nm). The structures consist of a thin Au stripe embedded in a transparent polymer film. When the polymer thickness is larger than the lateral extension of the plasmon, the stripe sustains a conventional long-range mode; in the opposite case, the mode is hybrid because its field distribution is confined by total internal reflection in the dielectric cladding. This hybridization increases the damping by absorption but dramatically reduces the radiation loss that occurs for curved geometries, such as bends. Our results are supported quantitatively by full-wave finite-element simulations.

We present a new plasmonic metasurface for simultaneous detection of polarization and spectrum of incident light. The demonstrated metasurface is a rationally designed cluster of artificial atoms that are engineered to exhibit polarization and wavelength-selective optical transmission. The fundamental building block of this structure is periodically coupled subwavelength aperture arrays with different orientations and lattice constants. When integrated with pixelated photodetectors, the metasurface can be used to measure the polarization and spectral information of an optical input. In this Letter, simultaneous detection of the polarization and spectrum of polarized light was experimentally demonstrated by analyzing the transmitted intensity distribution through the metasurface. The demonstrated metasurface offers great potential for many applications, such as polarimetric multispectral imaging and polarization-division multiplexing in optical communications.

We demonstrate enhanced sensitivity of a nanostructured plasmonic sensor that utilizes resonance in intentional structural defects within a plasmonic crystal. The measured sensitivity of the fabricated nanosensor is ∼500 nm/RIU showing improvement over traditional nanohole array sensors. Furthermore, the defects provide an additional design parameter to increase sensitivity by engineering plasmon lifetime.

Presented is a subwavelength surface plasmon polariton assisted resonant structure which supports a hybrid surface plasmon polariton Fabry-Perot (SPP-FP)-like wave. The hybrid resonator combines both plasmonic and optical resonance, resulting in a refractive index sensitivity enhancement of approximately 168%. The existence of hybrid SPP-FP modes with highly enhanced surface sensitivity is experimentally demonstrated.

We have designed, fabricated and characterized integrated directional couplers capable of converting the mode of an optical dielectric waveguide into a long-range plasmon propagating along a thin metal stripe. We demonstrate that the coupling between the two types of waveguides is generally very weak unless specific conditions are met. This sensitivity could be potentially exploited in sensing applications or for developing novel active photonic components.

This paper presents 1550-nm simulation results on the waveguided silicon-on-insulator four-port optical filtering and switching devices known as "SCISSOR" (an in-line array of microring resonators wherein each ring is coupled to two bus waveguides). We optimized the array number, the ring-bus coupling and the inter-ring spacing in order to obtain "rectangular" filter-passband shapes that have not heretofore been reported in the resonant-optics literature. We were able to engineer a box-like bandpass whose wavelength width could be anywhere from 5 to 50 % of the free spectral range (FSR). We then performed ring-bus apodization of the array that increased side-lobe suppression on the main filter band and widened the band. By reducing the FSR to 2.51 nm with increased ring diameter, we also showed that complete, high-extinction 2 x 2 optical switching is attained when the effective index of each ring in the group is changed by 2 x 10(-3), giving 1.02-nm shift of the 0.77-nm passband. Tunable filtering, sensing, reconfigurable add/drop and wavelength-division demultiplexing is offered in addition to switching.

Molecular-level understanding of the structure and the functions of the lymphatic system has greatly enhanced the importance of this second circulation system, especially in connection with cancer metastasis and inflammation. Recently, a third circulatory system, the primo vascular system (PVS) was found in various parts of an animal's body, especially as threadlike structures floating in the lymphatic flow in lymph vessels. Although the medical significance of this emerging system will require much work in the future, at present, several important suggestions in connection with immune cells, stem cells, and cancer metastasis have already appeared. Experiments to observe the PVS in the lymph vessels near the caudal vena cava of rabbits and rats have been performed by several independent teams, but reproduction requires considerable skill and technical know-how. In this article, we provide a detailed protocol to detect the PVS inside the lymph vessels of a rabbit. Detection and isolation are the first steps in unraveling the physiological functions of the PVS, which awaits intensive research.

We present unique characteristics of subwavelength surface plasmon polaritons in a periodically coupled nanowell structure. The nanowell structure offers high quality internal surface plasmon resonance for sensing applications. Calculated FWHM of the transmission peak is 6 nm and the optical transmission is close to 100% at the resonant wavelength of 815.8 nm. The highly concentrated polaritons in the nanowell are sensitive to surface changes providing a sensitivity of 4800% RIU(-1) for optical sensing applications.