Optical Fiber Array Research Articles

Optical fiber array based simultaneous parallel monitoring of resonant cantilever sensors in liquid

This paper reports a novel method for simultaneous resonance monitoring of MEMS cantilevers using phase based dynamic measurements without any electrical connections to the sensor array. MEMS cantilevers are made of electroplated nickel and actuated remotely with magnetic field using an electro-coil. To our knowledge this is the first demonstration of simultaneous parallel optical monitoring of dynamic mode micro-cantilever array in liquid environment. Illumination is generated using a laser source and a diffractive pattern generator, which provides 500μW laser power per channel. A compact fiber array based pick-up was built for optical readout. Its main advantages are easy customization to different size and pitch of sensor array, and good immunity to electrical noise and magnetic interference as the photo detectors are located away from the electro-coil. The resonant frequency of the cantilever is tracked with a custom multi-channel lock-in amplifier implemented in software. For demonstrating the stability and sensitivity of the system we performed measurements using glycerol solutions with different viscosities. Measured phase sensitivity was 0.9°/1% of Glycerol/DI-water solution and the standard deviation of measured phase was 0.025°. The resulting detection limit for Glycerol/DI-water solution was 280ppm. The proposed method showed robust results with low laser power and very good noise immunity to interference signals and environmental vibrations. The sensor technology demonstrated here is very significant as it is scalable to larger arrays for simultaneous and real- time monitoring of multiple biological and chemical agents during fluid flow.

Shock Sensitivity Studies for PBXN‐109

AbstractAn understanding of the explosive’s shock sensitivity is of vital importance for the hazard assessment and vulnerability evaluations of munitions. This paper summarizes the experimental and modeling research relating to shock initiation and sympathetic reaction of PBXN‐109. The modeling has focused on developing and applying Ignition and Growth (I&G) models using the hydrocode LS‐DYNA, taking into consideration the reduced shock sensitivity due to changes in source of ingredients. Detonation front tracking was applied to selected sympathetic reaction experiments and one Large Scale Gap Test series to extract additional information of the response of the acceptor charges. The simulated arrival times were compared with the measured data at the fibreoptic array positions. Finally, the shock sensitivity curve that summarizes the critical combination of peak shock pressure P and the derived parameter P2t was described for the PBXN‐109 formulations and compared with curves reported for other explosives.

A Subset of CD4/CD8 Double-Negative T Cells Expresses HIV Proteins in Patients on Antiretroviral Therapy.

ABSTRACTA major goal in HIV eradication research is characterizing the reservoir cells that harbor HIV in the presence of antiretroviral therapy (ART), which reseed viremia after treatment is stopped. In general, it is assumed that the reservoir consists of CD4+ T cells that express no viral proteins. However, recent findings suggest that this may be an overly simplistic view and that the cells that contribute to the reservoir may be a diverse population that includes both CD4+ and CD4− cells. In this study, we directly infected resting CD4+ T cells and used fluorescence-activated cell sorting (FACS) and fiber-optic array scanning technology (FAST) to identify and image cells expressing HIV Gag. We found that Gag expression from integrated proviruses occurred in resting cells that lacked surface CD4, likely resulting from Nef- and Env-mediated receptor internalization. We also extended our approach to detect cells expressing HIV proteins in patients suppressed on ART. We found evidence that rare Gag+ cells persist during ART and that these cells are often negative for CD4. We propose that these double-negative α/β T cells that express HIV protein may be a component of the long-lived reservoir. IMPORTANCE A reservoir of infected cells persists in HIV-infected patients during antiretroviral therapy (ART) that leads to rebound of virus if treatment is stopped. In this study, we used flow cytometry and cell imaging to characterize protein expression in HIV-infected resting cells. HIV Gag protein can be directly detected in infected resting cells and occurs with simultaneous loss of CD4, consistent with the expression of additional viral proteins, such as Env and Nef. Gag+ CD4− cells can also be detected in suppressed patients, suggesting that a subset of infected cells express proteins during ART. Understanding the regulation of viral protein expression during ART will be key to designing effective strategies to eradicate HIV reservoirs.

Development of a novel mixed hemimicelles dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene for the separation and preconcentration of fluoxetine in different matrices before its determination by fiber optic linear array spectrophotometry and mode-mismatched thermal lens spectroscopy

This study aims at developing a novel, sensitive, fast, simple and convenient method for separation and preconcentration of trace amounts of fluoxetine before its spectrophotometric determination. The method is based on combination of magnetic mixed hemimicelles solid phase extraction and dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene as a sorbent. The magnetic graphene was synthesized by a simple coprecipitation method and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The retained analyte was eluted using a 100 μL mixture of methanol/acetic acid (9:1) and converted into fluoxetine-β-cyclodextrin inclusion complex. The analyte was then quantified by fiber optic linear array spectrophotometry as well as mode-mismatched thermal lens spectroscopy (TLS). The factors affecting the separation, preconcentration and determination of fluoxetine were investigated and optimized. With a 50 mL sample and under optimized conditions using the spectrophotometry technique, the method exhibited a linear dynamic range of 0.4–60.0 μg L−1, a detection limit of 0.21 μg L−1, an enrichment factor of 167, and a relative standard deviation of 2.1% and 3.8% (n = 6) at 60 μg L−1 level of fluoxetine for intra- and inter-day analyses, respectively. However, with thermal lens spectrometry and a sample volume of 10 mL, the method exhibited a linear dynamic range of 0.05–300 μg L−1, a detection limit of 0.016 μg L−1 and a relative standard deviation of 3.8% and 5.6% (n = 6) at 60 μg L−1 level of fluoxetine for intra- and inter-day analyses, respectively. The method was successfully applied to determine fluoxetine in pharmaceutical formulation, human urine and environmental water samples.

Display glass for low-loss and high-density optical interconnects in electro-optical circuit boards with eight optical layers.

Parallel optical interconnects on-board level requires low propagation loss in wavelength range between 850 and 1550 nm to be compatible with datacom and telecom optical engines. For highest integration density tight waveguide bends and a scalable number of optical layers should be manufacturable for 2D interfaces to optical fiber array connectors and photonic assembly I/O's. We developed a glass waveguide panel process for double-sided processing of commercial available display glass by applying a two-step thermal ion-exchange process for low-loss multi-mode graded-index waveguides. Multiple glass waveguide panels can be embedded between electrical layers. The generic concept enables fabrication of high-density integration (HDI) electro-optical circuit boards (EOCB) with high number of optical and electrical layers. Waveguides with high NA of 0.3 for low bend losses could be achieved in glass with propagation loss of 0.05 dB/cm for all key wavelengths. Four of those glass waveguide panels were embedded in an EOCB demonstrator with size of 280 x 233 mm² providing eight optical layers with 96 channels in an area of 2.8 x 1.5 mm². To the best of our knowledge it's the highest number of layers that has ever been demonstrated for an EOCB.

Abstract LB-C08: Exploring glycan markers for immunotyping and precision-targeting of breast circulating tumor cells (CTCs)

Abstract Recognition of abnormal glycosylation in virtually every cancer type has raised great interest in exploration of the tumor glycome for biomarker discovery. Identifying glycan markers of circulating tumor cells (CTCs) represents a new development in tumor biomarker discovery. The aim of this study was to establish an experimental approach to enable rapid screening of CTCs for glycan marker identification and characterization. We applied carbohydrate microarrays and a high-speed fiber-optic array scanning technology (FASTcell) to explore potential glycan markers of breast CTCs (bCTCs) and targeting antibodies. An anti-tumor monoclonal antibody, HAE3-C1 (C1), was identified as a key immunological probe in this study. In our carbohydrate microarray analysis, C1 was found to be highly specific for an O-glycan cryptic epitope, gpC1. Using FASTcell technology, we established a procedure to quantify expression levels of gpC1 in tumor cells. In blood samples from five Stage IV metastatic breast cancer patients, the gpC1 positive CTCs were detected in all subjects; approximately 40% of bCTCs were strongly gpC1 positive. Interestingly, the CTCs from a triple-negative breast cancer patient with multiple sites of metastasis were predominantly gpC1 positive (92.5%, 37/40 CTCs). Taken together, we present here a practical approach to examine rare cell expression of glycan markers. Using this approach, we identified an O-core glyco-determinant gpC1 as a potential immunological target of bCTCs. Given its bCTC-expression profile, this target warrants an extended investigation in a larger cohort of breast cancer patients. Citation Format: Lidia C. Sambucetti, Xiaohe Liu, Ben Hsieh, Richard Bruce, George Somlo, Jiaoti Huang, Denong Wang. Exploring glycan markers for immunotyping and precision-targeting of breast circulating tumor cells (CTCs). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-C08.

Use of fiber Bragg grating array and random decrement for damage detection in steel beam

A growing trend in the use of fiber Bragg grating array to detect structural damage has been observed in recent years. This paper describes the use of fiber Bragg grating optical sensors in an array to identify the location and assess the extent of damage on steel structures. A fiber optical sensing array with eight sensing elements has been designed, fabricated, and applied to measure the time history of strain at different points on a simply supported beam subjected to random loading. The wavelength shifts of the sensors are used to calculate the strain distribution along the beam. The random decrement at each point, for different modes, is extracted from the time history of the responses. The random decrements are compared at different damage ratios to an intact case to identify the existence of damage. Multichannel random decrement is applied to extract excited mode shapes. The mode shapes are then used to determine the location of the damage. The results show that the fiber optical sensor array is a reliable, fast, and accurate tool for the identification and localization of damage by using strain measurements.

Exploring Glycan Markers for Immunotyping and Precision-targeting of Breast Circulating Tumor Cells

Recognition of abnormal glycosylation in virtually every cancer type has raised great interest in exploration of the tumor glycome for biomarker discovery. Identifying glycan markers of circulating tumor cells (CTCs) represents a new development in tumor biomarker discovery. The aim of this study was to establish an experimental approach to enable rapid screening of CTCs for glycan marker identification and characterization. We applied carbohydrate microarrays and a high-speed fiber-optic array scanning technology (FAST scan) to explore potential glycan markers of breast CTCs (bCTCs) and targeting antibodies. An anti-tumor monoclonal antibody, HAE3-C1 (C1), was identified as a key immunological probe in this study. In our carbohydrate microarray analysis, C1 was found to be highly specific for an O-glycan cryptic epitope, gp(C1). Using FAST-scan technology, we established a procedure to quantify expression levels of gp(C1) in tumor cells. In blood samples from five stage IV metastatic breast cancer patients, the gp(C1) positive CTCs were detected in all subjects; ∼40% of bCTCs were strongly gp(C1) positive. Interestingly, CTCs from a triple-negative breast cancer patient with multiple sites of metastasis were predominantly gp(C1) positive (92.5%, 37/40 CTCs). Together we present here a practical approach to examine rare cell expression of glycan markers. Using this approach, we identified an O-core glyco-determinant gp(C1) as a potential immunological target of bCTCs. Given its bCTC-expression profile, this target warrants an extended investigation in a larger cohort of breast cancer patients.

Iron oxide functionalized graphene oxide as an efficient sorbent for dispersive micro-solid phase extraction of sulfadiazine followed by spectrophotometric and mode-mismatched thermal lens spectrometric determination

A simple and rapid dispersive micro-solid phase extraction (DMSPE) combined with mode-mismatched thermal lens spectrometry as well as fiber optic linear array spectrophotometry was developed for the separation, extraction and determination of sulfadiazine. Graphene oxide was synthesized using the modified Hummers method and functionalized with iron oxide nanoparticles by means of a simple one step chemical coprecipitation method. The synthesized iron oxide functionalized graphene oxide was utilized as an efficient sorbent in DMSPE of sulfadiazine. The retained analyte was eluted by using 180µL of a 6:4 mixture of methanol/acetic acid solution and was spectrophotometrically determined based on the formation of an azo dye through coupling with thenoyltrifluoroacetone. Under the optimized conditions, with the application of spectrophotometry technique and with a sample volume of 100mL, the method exhibited a linear dynamic range of 3–80µgL−1 with a detection limit of 0.82µgL−1, an enrichment factor of 200 as well as the relative standard deviations of 2.6% and 4.3% (n=6) at 150µgL−1 level of sulfadiazine for intra- and inter-day analyses, respectively. Whereas, through the application of the thermal lens spectrometry and a sample volume of 10mL, the method exhibited a linear dynamic range of 1–800µgL−1 with a detection limit of 0.34µgL−1 and the relative standard deviations of 3.1% and 5.4% (n=6) at 150µgL−1 level of sulfadiazine for intra- and inter-day analyses, respectively. The method was successfully applied to the determination of sulfadiazine in milk, honey and water samples.

Protocol of networks using energy sharing collisions of bright solitons

It is well known that solitons in integrable systems recover their original profiles after their mutual collisions. This is not true in the case of optical fibre arrays, governed by a set of integrable coupled nonlinear Schrodinger (CNLS) equations. We consider the Manakov- and mixed-type ‘two-component’ CNLS systems. The most important characteristics of these systems are: (1) The polarizations of the two-component solitons are changed through their mutual collisions (Manakov system) and (2) the energy (intensity) switching occurs through the head-on collision (mixed system). By placing the above solitons on the primary star graph (PSG), we see that soliton collisions give rise to interesting phase changes in PSG: (a) The transition in PSG from its depolarized state to polarized one; (b) a state with selectively amplified bond is generated on PSG from its homogeneous state. These results will be applicable to network protocols using optical fibre arrays.

Automated visual position detection and adjustment for optical waveguide chips and optical fiber arrays

The alignment coupling between optical waveguide chips and optical fiber arrays is the basis of the alignment coupling of planar optical waveguide devices, and the precise position detection with angle and spacing adjustments is one of the key steps of alignment coupling. A methodology for position detection, and angle and spacing adjustment was proposed for optical waveguide chips and optical fiber arrays based on machine vision. The experimental results show angle detection precision levels higher than 0.05°, line detection precision levels higher than 0.1 μm, and detection time less than 2 s. Therefore, the system developed herein meets the precise requirements necessary for position detection, and angle and spacing adjustments for optical waveguide chips and optical fiber arrays.

A Fiber-Optic System for the Quasi-Distributed Detection of Liquids

This letter presents a multiplexed fiber-optic sensor array suitable for detection of liquid intrusions, spills, and leaks. The proposed detection systems is based on active heating and observation of temperature changes in short sections of optically absorbing (vanadium-doped) optical fibers that were interconnected into a sensing array by a standard single-mode optical fiber. The heating of the vanadium-doped fiber sections was achieved by application of a common 980-nm pump laser source. The associated signal processing and integration utilizes a simple, custom-designed optical time domain reflectometry that relies on only a few low-cost standard telecom components.

Reactive molten core fabrication of glass-clad Se(0.8)Te(0.2) semiconductor core optical fibers.

Phosphate glass-clad optical fibers comprising amorphous Se(0.8)Te(0.2) semiconductor core were fabricated by a reactive molten core approach. The Se(0.8)Te(0.2) crystals were precipitated in core region by a postdrawing annealing process, which were confirmed by X-ray diffraction, micro-Raman spectra, electron probe X-ray micro-analyzer, and transmission electron microscope measurement results. A two-cm-long crystalline Se(0.8)Te(0.2) semiconductor core optical fiber, electrically contacted to external circuitry through the fiber end facets, exhibits a two-orders-of-magnitude change in conductivity between dark and illuminated states. The great discrepancy in light and dark conductivity suggests that such crystalline Se(0.8)Te(0.2) semiconductor core optical fibers have promising applications in optical switch and photoconductivity of optical fiber array.

사냑형 간섭계 광섬유 센서를 이용한 변압기유 내에서의 외부 음향 주파수 모니터링

The fiber optic Sagnac interferometer is well established as a sensor for detection of physical perturbations such as acoustic and vibration. In this paper acoustic signals generated in the cylindrical cavity submerged in transformer oil were measured by the fiber optic sensor array in one Sagnac loop. Two different external sound frequencies, and , were applied to the sensor array simultaneously by using piezoelectric with frequency range from 5 kHz to 90 kHz. Based on the experimental results, fiber optic sensor detected harmonic series of applied sound frequency such as , , , , , . Suggested fiber optic sensor array can be applied to monitor physical quantities such as internal sound pressure and vibration due to partial discharge in the real electric transformer system.

Application of the ABCD ray matrix method for the design of a refractive 2.5× beam expander–focuser used for coupling laser beams into a 5 × 4 fiber-optic array: Comparison with Zemax Gaussian and geometrical optics calculations

In this article, an approach for the design and construction of a refractive 2.5× Galilean beam expander–focuser system which incorporates a two-axis galvanometer for coupling non-collinear laser beams into a 5×4200μm core diameter fiber-optic array is discussed. M2 Gaussian beam waist and beam waist location computations using the ABCD ray matrix and Zemax® paraxial Gaussian optics methods are given. Using the described optical system a 532nm and 637nm laser beams are coupled noncollinearly into 200μm core diameter fiber array by focusing down the laser beams to 71.26±3.18m and 90.32±4.28μm diameter spots, respectively. Furthermore, an experimental validation for the focused beam size calculations using a knife-edge profilemeter is provided. The measured average transmission for the fibers in the fiber-optic array is 92.54±3.78% (maximum FCE (fiber coupling efficiency): 99%; minimum FCE: 82%). Whereas the Zemax® calculated geometric ray-optics fiber coupling efficiency for the beam expander-focuser into a 200μm core diameter fiber using uncoated lenses and without accounting for Fresnel reflections and bulk absorption effects is 100%. Geometric ray-optics calculations indicate that Fresnel reflections and bulk absorption effects account for 7% of the 100% FCE value. The described optical switching scheme which incorporates a galvanometer is used for exciting asynchronously 20 PCR (Polymerase Chain Reaction) vessels in high throughput DNA/RNA amplification systems.

Wafer-scale pixelated scintillator and specially designed data acquisition system for fiber optic taper array-coupled digital x-ray detector

A digital x-ray detector scheme based on a pixelated scintillator coupled with a fiber optic (FOT) array is suitable for many high-resolution x-ray imaging applications. However, certain challenges need to be addressed for fabrication of wafer-scale uniform pixelated x-ray scintillators. In addition, difficulties associated with implementation of the data acquisition system for acquiring output image data from the multiple image sensors used in the detector also need to be addressed. In this paper, a 2×2 FOT array-coupled digital x-ray detector scheme using a 5-in. pixelated scintillator is proposed. A novel fabrication setup along with the corresponding processes for fabricating the wafer-scale pixelated scintillator and implementation of a specially designed embedded data acquisition system based on a single embedded micro-processer (ARM) and four field-programmable gate array (FPGA) chips are discussed in detail. Preliminary experiments demonstrate that this pixelated scintillator-based digital x-ray detector scheme with an active imaging area of about 100mm×100mm shows considerable potential for use in high-resolution x-ray imaging.

Processes for design, construction and utilisation of arrays of light-emitting diodes and light-emitting diode-coupled optical fibres for multi-site brain light delivery.

Optogenetics enables light to be used to control the activity of genetically targeted cells in the living brain. Optical fibers can be used to deliver light to deep targets, and LEDs can be spatially arranged to enable patterned light delivery. In combination, arrays of LED-coupled optical fibers can enable patterned light delivery to deep targets in the brain. Here we describe the process flow for making LED arrays and LED-coupled optical fiber arrays, explaining key optical, electrical, thermal, and mechanical design principles to enable the manufacturing, assembly, and testing of such multi-site targetable optical devices. We also explore accessory strategies such as surgical automation approaches as well as innovations to enable low-noise concurrent electrophysiology.

Clinical immunosensing of tuberculosis CFP-10 antigen in urine using interferometric optical fiber array

The CFP-10 antigen (Ag), found in the tissue fluids of tuberculosis (TB) patients, is an excellent candidate marker for early and simplified diagnosis of TB when combined with an effective sensing method. In this study, clinical level immunosensing of CFP-10 in urine samples from TB patients was performed using a self-assembled interferometric optical fiber array system. To generate the immunosensing interface, two directions of assay designs were introduced: (I) the direct immobilization of anti-CFP-10 monoclonal antibody (mAb) on a fiber tip surface, (II) the indirect conjugation of anti-CFP-10 mAb with the assistance of primary capture layer. Then, the orientation and accessibility of the antibody were assessed by the selective binding of CFP-10 to this interface. The results revealed a linear relationship between the optical phase shift of the interferometric sensing system and the acid-fast bacilli (AFB) staining stage (0–3) of the TB patients. Significant differences were observed between urine samples from infected and non-infected patients. This method, which uses urine samples and an interferometric sensing system, allows fast and ultrasensitive clinical monitoring and can be rapidly developed into a reliable diagnostic method to monitor TB infection.

Ultradense Silicon Photonic Interface for Optical Interconnection

A scalable ultradense silicon photonic interface with 61 compact vertical grating couplers on a pitch of 42.3 μm is designed and fabricated to match a pitch reducing optical fiber array (PROFA) hexagonal channel pattern. Experimental results show that the designed grating couplers with a minimum insertion loss of 4.5 dB and a 3-dB bandwidth of 50 nm are obtained. The crosstalk between different channels is less than -50 dB and the maximum loss difference across the PROFA interface is ~0.7 dB. High-speed data transmission indicates that a bandwidth density as large as 27 Tb/s/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> could be achieved within a footprint of 0.096 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , demonstrating the potential of silicon photonics for broadband optical interconnection.

Spatiotemporal optical bullets in two-dimensional fiber arrays and their stability

Long-lived light bullets fully localized in both space and time can be generated in novel photonic media such as multicore optical fiber or waveguide arrays. In this paper we present detailed theoretical analysis on the existence and stability of the discrete-continuous light bullets using a very generic model that occurs in a number of applications.