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In this study, a novel gradient grating period guided-mode resonance (GGP-GMR) biosensor is proposed, and albumin was successfully detected as a test model. The GGP-GMR sensor exhibits a gradient resonant wavelength along the device. At a fixed incident wavelength, light resonates at a specific period such that the light is reflected at this period (or resonant period) and transmitted to other periods. Thus, for a charge-coupled device under the GGP-GMR sensor, a dip-like intensity distribution was measured with a specific pixel of minimum intensity corresponding to the resonant period. The variation in sample concentrations caused changes in the refractive index (RI) on the sensor surface, which induced a shift in the resonant period and in the pixel corresponding to the minimum intensity. A GGP-GMR sensor can achieve a limit of detection of $8.58\times 10^{{-4}}$ RIU within a detection range of sucrose solutions of 0%–60% concentrations that corresponds to the RI from 1.333 to 1.442. In a buffer solution, albumin was successfully detected to measure the clinically relevant concentration. The simple design and easy fabrication of the GGP-GMR sensor combined with its simple readout and optical path design facilitates system miniaturization for handheld devices and its integration with smartphones, which could be beneficial for future point-of-care applications.

In this study, we demonstrated a hydrogen (H2) sensor based on a guided-mode resonance (GMR) filter coated with a layer of palladium (Pd). The sensor consists of three key layers, namely the substrate (replicated grating structure on an optical adhesive), waveguiding layer of TiO2, and active-sensing layer of Pd. The sensor functions as an optical resonator. On absorption of H2, the change of the refractive index in Pd changes the optical response of the sensor. To monitor the output optical response, a transmission setup was used, and two detection modalities—the change in transmission efficiency at a specific wavelength and the shift in the resonant wavelength—were demonstrated. Upon injection of a mixture of 4% H2 and 96% argon, the resonant wavelength shifted 6.38 nm, and transmission efficiency increased by 45% in 24 s.

In this letter, we introduce a novel refractive index sensor based on gradient grating period guided-mode resonance (GGP-GMR). Rather than a constant grating period, as in typical GMR, GGP-GMR comprises a grating period varying in increments of 2 nm. For grating variation from 386 to 392 nm, a detection range of 0.109 RIU with a bulk sensitivity of 1433.7 $\mu \text{m}$ /RIU and theoretical and experimental detection limits of $5.58 \times 10^{-3}$ and $10^{-2}$ RIU, respectively, can be achieved. Several tactics that can be readily adopted are suggested to improve the limit of detection by an order of $10^{-4}$ RIU, sufficient for detecting many clinically relevant biomarkers. The readout system requires a narrow band of light and a simple charge-coupled device combined with the compact design of the GGP-GMR sensor, which eases the miniaturization of the system for handheld devices as well as its integration with smartphones.

This paper reports a method for micrometer-scale linear and angular displacement measurement based on a gradient grating period guided-mode resonance (GGP-GMR) filter. When the filter is mounted on a moving or rotating object, the displacement on the object can be observed through the changes in the resonant wavelength, which are detected by the GGP-GMR filter. In this paper, the GGP-GMR filter comprised grating periods from 250 to 550 nm with 2-nm increments. Each period comprised 100 repeated cycles, resulting in a total length of 6 mm. For linear displacement, we achieved an average sensitivity of 67 nm/mm for a detection range of 6 mm and a theoretical limit of detection of $3~\mu \text{m}$ . To demonstrate the measurement of angular displacement, the GGP-GMR filter was attached to a cylinder with a diameter of 8 cm. The experimental results revealed an average sensitivity of 51.7 nm/° for a range of 7° and an experimental limit of detection of 0.002°.

In this article, a novel refractive index sensor based on gradient waveguide thickness guided-mode resonance (GWT-GMR) is proposed. The GWT can convert an spectral information into an spatial information, which can be measured using a charged coupled device (CCD) instead of a bulky spectrometer. A GWT-GMR sensor of size only 1261 200m2 has a detection range of 0.109 refractive index units (RIU), sensitivity of 16239mRIU, and the limit of detection of 6.9 104RIU, which are sufficient for many practical applications. Multiplexing can be easily implemented because of sensor compactness and the simple readout of the CCD. Moreover, the system is suitable for handheld devices or integration with smartphones for potential biosensing applications.

This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

An optical pH sensor is developed with the coating of second layer to eliminate leaching effect. A great linearity and reproducibility of pH resolution in physiological range is demonstrated.

A fine cylindrical chemical sensor tip is developed with optical fiber in the core, surrounded by a transparent cylinder of photopolymer Norland Optical Adhesive 61 (NOA 61), and covered by a polymer hydrogel mixed with sensing molecules. The overall diameter is as small as 1.5 mm. pH response is demonstrated using two approaches of sensing materials: (i) absorbing probe Phenol Red mixed with Rhodamine 6G fluorescent dye and (ii) 8-hydroxypyrene-1,3,6-trisulfonic acid fluorescent probe. Both the optical excitation and fluorescence signal collection are through the optical fibers. A time resolution of 10 s is achieved for pH variations. Good linearity is observed in the physiological range from pH 7.0 to pH 8.6 with reversible and reproducible outcomes. For in vitro urea measurement, the sensor tip can distinguish 1, 3, and 5 mM urea solution, which is a crucial range in saliva urea concentration. The miniaturized tip with such simple cylindrical symmetry is designed to detect vital signs during minimally invasive surgeries and can be potentially accompanied with endoscopes to enter human bodies.

Solid-state zinc ion sensor is developed with high enough resolution and reproducibility for the potential application in brain injury monitoring. An optical diffuser is incorporated into the zinc ion sensor based on optical fiber and hydrogel doped with the fluorescent zinc ion probe molecule meso-2,6-Dichlorophenyltripyrrinone (TPN-Cl2). The diffuser transforms the high-peak-intensity excitation light near the fiber end into a broad light with moderate local intensity to reduce the degradation of the probe molecule. Reversible detection can be reached for 1, 2, and 5 μM (10−6 Molar), with slopes 0.3, 0.6, and 0.8 respectively. This is the pathophysiological concentration range after brain injury. The sensor is applied to neuron-glial cultures and macrophage under the stimulation of lipopolysaccharide (LPS), KCl and oxygen/glucose deprivation (OGD) that reflect inflammation, depolarization and ischemia respectively, mimicking events after brain injury. The zinc ion level is raised to 4–5 μM after LPS treatment, and then reduced to

This paper reports a compact spectrometer based on a guided-mode resonance (GMR) filter mounted on a linear charge-coupled device (CCD). The GMR is specially designed to exhibit gradient grating periods (GPPs) laterally to ensure that the GMR functions as a linear-variable bandstop filter. Each period corresponds to a resonant wavelength such that this wavelength is reflected back at its corresponding resonant period and transmitted to all other periods. Consequently, when a resonant wavelength is incident on the GGP-GMR attached to a linear CCD, the CCD pixel underneath its resonant period receives the minimum intensity, and the other pixels receive higher intensities. In terms of the wavelength range of interest, by scanning a single wavelength at a time, a transmission efficiency matrix that contains the transmission efficiency of each wavelength at each pixel can be established. An unknown incident spectrum can be reconstructed using the established transmission efficiency matrix and the intensity measured using the CCD. In this study, a GGP-GMR spectrometer less than 3 mm long that can achieve a wavelength detection range of 200 nm was demonstrated to reconstruct various incident spectra, including a single wavelength of light with a resolution of 0.5 nm, a single wavelength of light with varying intensity levels, and dual incident light sources.

A novel biosensor based on a two-dimensional gradient (TDG) guided-mode resonance (GMR) filter was introduced in this study. The TDG-GMR is demarcated in terms of the gradient grating period (GGP) in one dimension and gradient waveguide thickness (GWT) in the other dimension. A single compact sensor can combine these two features to simultaneously provide a broad detection range through GGP and high resolution through GWT. A detection range of 0.109 RIU (0%–60% sucrose content) with a limit of detection of 5.62 × 10−4 was demonstrated in this study by using a TDG-GMR with a size of 140.8 × 125.4 µm2. This value cannot be achieved using one dimensional gradient GMR sensor. Label-free (LF) biomolecule detection through TDG-GMR was also experimentally demonstrated in a model assay of albumin. The result confirms that the GWT-GMR provides a better resolution, whereas the GGP-GMR provides a broader detection range. A device for multiplex measurement could be easily implemented with a compact sensor chip and a simple readout directly from a charge-coupled device. This system would require a narrow-band source such as a light emitting diode or a laser diode, in addition to a limited number of other components such as a polarizer and a collimator. The proposed TDG-GMR could easily be integrated with smartphones and portable devices.

Portable systems for detecting biomolecules have attracted considerable attention, owing to the demand for point-of-care testing applications. This has led to the development of lab-on-a-chip (LOC) devices. However, most LOCs are developed with a focus on automation and preprocessing of samples, fluorescence measurement, which requires additional off-chip detection instruments, remains the main detection method in conventional assays. By incorporating optical biosensors into LOCs, the biosensing system can be simplified and miniaturized. However, many optical sensors require an additional coupling device, such as a grating or prism, which complicates the optical path design of the system. In this study, we propose a new type of biosensor based on gradient waveguide thickness guided-mode resonance (GWT-GMR), which allows for the conversion of spectral information into spatial information such that the output signal can be recorded on a charge-coupled device for further analysis without any additional dispersive elements. A two-channel microfluidic chip with embedded GWT-GMRs was developed to detect two model assays in a buffer solution: albumin and creatinine. The results indicated that the limit of detection for albumin was 2.92 &mu, g/mL for the concentration range of 0.8&ndash, 500 &mu, g/mL investigated in this study, and that for creatinine it was 12.05 &mu, g/mL for the concentration range of 1&ndash, 10,000 &mu, g/mL. These results indicated that the proposed GWT-GMR sensor is suitable for use in clinical applications. Owing to its simple readout and optical path design, the GWT-GMR is considered ideal for integration with smartphones or as miniaturized displays in handheld devices, which could prove beneficial for future point-of-care applications.

Dilution is a common procedure in biological and chemical analyses to perform tests at different concentrations. In previously reported micro diluters, although they could provide a wide dilution range, only limited dilution ratios were demonstrated, i.e. low flexibility in dilution ratio. Here, a droplet-based micro diluter with high flexibility on dilution ratio is proposed, fabricated, and tested. Through combination of five different electrode sizes using electrowetting-on-dielectric (EWOD) technique, the proposed micro diluter can provide 49 dilution ratios at dilution range from 1/2 to 1/50. Experimental results verify that different dilution ratios can be successfully generated, even at the most difficult low concentration range. Comparing to the design with equal electrode size in conventional EWOD-based microfluidic chip, the proposed design with unequal electrode sizes can reduce the operation steps to achieve high flexibility on dilution ratios efficiently.

In this Letter, we demonstrate that by adjusting the thickness of the buffer layer, the optical responses of a guided-mode resonance filter (GMRF) can be improved for sensor applications. The GMRF is fabricated using a replica molding with a plastic substrate and a UV-curable polymer. SiO2 buffer layers of different thicknesses are deposited before the waveguide-layer deposition. The sensitivity of the GMRFs decreases slightly with increasing SiO2 layer thickness. By contrast, the full width at half-maximum reduces substantially with increasing SiO2 layer thickness, resulting in the improvement of the overall figure of merit.

We present an integrated microfluidic system consisting of a label-free biosensor of a guided-mode resonance filter (GMRF) and a microfluidic channel with a micropost filter. The GMRF was fabricated through replica molding using an ultraviolet-curable polymer and a plastic substrate. An array of microposts (a diameter and height of 26.5 and 56 μm, respectively, and a spacing between 7.5 and 9.5 μm), fabricated on a silicon substrate through photolithography, was used as the filter. A double-sided tape was used to laminate the GMRF and a microfluidic chip such that the integrated device provides two functions: filtration of the cell debris and quantification of the in-cell protein concentration. By measuring the changes in the resonant wavelength from the GMRF, the detection of β-actin in an unprocessed lysed cell sample was demonstrated; the cell debris was separated using the micropost filter to prevent false measurement.

A resonant wavelength detection system based on a gradient grating period guided-mode resonance (GGP-GMR) filter and a linear charge-coupled device is demonstrated. The GGP-GMR used in this work consists of a subwavelength grating structure with a grating period varying from 250–550 nm in increments of 2 nm. We successfully demonstrate that by using this system, we can monitor the shift in a biosensor’s dip wavelength caused by different sucrose concentrations. This technology has the potential to replace a bulky and expensive spectrometer used in most optical biosensor systems. Given its compactness, the system can be integrated with lab-on-a-chip systems for numerous biosensing applications.

We demonstrate the detection of C-creative protein (CRP) from whole blood samples without sample pretreatment by using a lab-on-a-chip system consisting of a microfluidic chip and a label-free biosensor. The microfluidic chip includes an array of microposts for filtering blood cells and allows only plasma to flow through and reach the guided-mode resonance (GMR) biosensor for real-time monitoring. The developed GMR sensor can achieve a bulk sensitivity of 186 nm RIU-1, which supports a limit of detection of 3.2 ng mL-1 for recombinant CRP spiked in human serum. The results are comparable with those obtained using enzyme-linked immunosorbent assay. In addition, we demonstrate the efficacy of filtration of blood cells using microposts and simultaneous measurement of CRP concentration using a GMR sensor by using whole blood and plasma samples.

We combine photonic crystal and magnetic beads aggregation enhanced fluorescence for extremely sensitive detection of biomolecules in bead-based assay format. The limit of detection for Interleukin 1β can achieve 100 ag/ml.

We demonstrate a Lab-on-a-chip (LOC)system for whole blood sensing. The LOC consists of a microfluidic chip including an array of microposts for cell filtration and a label-free guided-mode resonance biosensor for real-time quantification.

We designed and fabricated a compact spectrometer based on a gradient grating period guided-mode resonance filter (GGP-GMRF). The GGP-GMRF of 2.23 mm long consisted of gratings with periods varying from 250–388 nm in 2-nm increments. With such compact size, the device can measure spectrum ranging from 506 to 700 nm.

In this study, we designed, fabricated and demonstrated a compact wavelength detection system based on a gradient grating period guided-mode resonance filter (GGP-GMRF) mounted on a linear charge-coupled device (CCD) camera. The GGPGMRF was first fabricated through nanoreplica molding on a plastic substrate, followed by the deposition of a thin TiO 2 film. The grating periods of the GGP-GMRF vary from 250 to 550 nm with a 2 nm increment in each period consisting of 100 cycles. The results show that a 6 mm long GGP-GMRF has a filtering range of 506 to 915 nm. Upon illumination, the GGP-GMRF reflects a particular wavelength of light resulting in the minimum transmission of that wavelength. Hence, the GGP-GMRF provides a spatially dependent minimum transmission depending on the wavelength of the incident light. The linear CCD underneath the GGP-GMRF measures the transmitted intensity, and the wavelength of the incident light can be correlated with the location of the minimum intensity. For the demonstrated GGP-GMRF and CCD system, a spectral resolution of 1 nm can be achieved.

We demonstrate a compact spectrometer system by using a gradient grating period guided-mode resonance filter—mounted on a linear photodetector array—that exhibits spatially dependent resonance characteristics; a specific incident wavelength is reflected such that the underlying array pixels measure minimum intensity. A precalibrated transmission efficiency matrix is used to determine each pixel’s transmission efficiency for specific wavelengths. Unknown spectral information can be calculated from the measured intensity. Grating periods of 250–388 nm in 2-nm increments are used in each 100-cycle period. Device length is 2.23 mm. Spectral range of 506–700 nm is measurable with 1-nm resolution.

We designed a linear filter based on a gradient grating period guided-mode resonance. By incorporating this device with a photodetector, the system can measure wavelength ranging from 500 to 700 nm with 1 nm resolution.

A process that combines polymer nanoreplica molding with horizontal dipping was used to fabricate large area (~ 3 × 5 inch2) distributed feedback laser biosensors (DFBLB) on flexible plastic substrates, which were subsequently incorporated into standard format 96-well microplates. A room temperature nanoreplica molding process was used to create subwavelength periodic grating structures, while a horizontal dipping process was used to apply a ~ 300 nm, dye-doped polymer film. In this work, the DFBLB emission wavelength, used to characterize the device uniformity, demonstrated a coefficient of variation (CV) of 0.41% over the fabricated device area, representing a thickness standard deviation of only ~ 35 nm for the horizontal dipping process. The fabricated sensors were further characterized for sensitivity uniformity by measuring the bulk refractive index of the media exposed to the sensor surface and by measuring adsorption of biomolecular layers. An assay for detection of the cytokine Tumor Necrosis Factor-alpha (TNF-α) was used to demonstrate the operation of the sensor in the context of label-free detection of a disease biomarker. The demonstrated capability represents an important step towards roll-to-roll manufacturability for this biosensor that simultaneously incorporates high sensitivity with excellent wavelength shift resolution, and adaptability to the microplate format that is ubiquitous in pharmaceutical research.

We report on the use of photonic crystal surfaces as a high-sensitivity platform for detection of a panel of cancer biomarkers in a protein microarray format. The photonic crystal surface is designed to provide an optical resonance at the excitation wavelength of cyanine-5 (Cy5), thus providing an increase in fluorescent intensity for Cy5-labeled analytes measured with a confocal microarray scanner, compared to a glass surface. The sandwich enzyme-linked immunosorbent assay (ELISA) is undertaken on a microarray platform to undertake a simultaneous, multiplex analysis of 24 antigens on a single chip. Our results show that the resonant excitation effect increases the signal-to-noise ratio by 3.8- to 6.6-fold, resulting in a decrease in detection limits of 5–90%, with the exact enhancement dependent upon the antibody-antigen interaction. Dose-response characterization of the photonic crystal antibody microarrays shows the capability to detect common cancer biomarkers in the < 2 pg/ml concentration range within a mixed sample.

We present SU-8 as an optical waveguide and its integration into a functional one- and two-dimensional (1-D and 2-D) scanning device. The waveguide is fabricated as a tapered structure and cantilever beam (100times85times2100 mum). It is mounted onto a 2-D coupled bimorph piezoelectric actuator and driven at resonant frequencies of 4.71 kHz in the vertical and 25 Hz in the horizontal. This raster motion allows for 2-D image scanning when in combination with a light source and detector. An analysis of the polymer's optical capabilities has shown mode coupling efficiencies of 96% and measured a total power output intensity of 20% with a 633-nm light source. The output power can be attributed to the butt-end coupling misalignment, scattering losses due to surface roughness, and absorption. The total vertical tip displacement is 669 mum with an angle of 25 deg when driven with a 47-mum base excitation. A specific application for the design is in the area of endoscopy, where there is a need for a minimally invasive device that reduces the discomfort experienced by the patient. SU-8 as the functional waveguide is the initial phase in creating a microfabricated endoscope system

In this paper, we demonstrate that the fluorescence collection efficiency of surface-bound fluorophores can be enhanced through coupling of fluorescence emission into both TE and TM resonant modes of a photonic crystal substrate.

We demonstrate a digital microfluidic system with an on-chip detection capability that is based on a guided-mode resonance filter (GMRF). Versatile droplet manipulation was achieved through the electrowetting-on-dielectric (EWOD) technique. GMRF was fabricated through replica molding and soft lithography, and the EWOD chip was fabricated through a typical photolithography process. Droplets measuring 1.125 µL were used to demonstrate merging, mixing, and cutting, and to achieve twofold and Threefold dilutions, and were then transported to the GMRF region for concentration measurement. The bulk sensitivity of GMRF is approximately 90 nm RIU−1 [17494 nm/(g/L)], resulting in a minimum detectable concentration of 4.66 × 10−5 g/L for a sucrose solution.

This study demonstrates a photonic crystal micropost (PCMP) substrate for microarray applications. The substrate comprises an array of circular MPs with a PC on top of these MPs. This substrate enables biomolecule-containing droplets to form a composite contact upon deposition, thus allowing biomolecules to be attached on only the MPs, forming spots. When the device (PC) is excited on resonance, the electric field intensity is enhanced on only the top surface of the MPs. This enables the fluorescence intensities to be enhanced up to 5.50x; principally, this enhancement does not engender an increase in the background (intensity outside MP or spots) and noise intensities. The PCMP substrate enhances the spot intensity and minimizes the background intensity, enabling the detection of lower concentration analytes.

In this letter, we fabricated and characterized a linear variable filter based on a guided-mode resonance filter (GMRF) with gradient grating periods. The GMRF was first fabricated through nanoreplica molding on a plastic substrate, which was followed by the deposition of a thin TiO2 film. The grating periods of the GMRF vary from 250 to 550 nm with a 2-nm increment in each period consisting of 100 cycles. The results show that a 6-mm-long GMRF has a filtering range of 506–915 nm.

We report for the first time the combination of a quartz-based photonic crystal (PC) with a detection instrument designed to perform label-free (LF) and enhanced fluorescence (EF) imaging for antibody microarray applications. Label-free detection is used to quantify binding density of immobilized capture antibodies. Angle-scanning approach is implemented to achieve more uniform fluorescence enhancement by reducing the coefficient of variation of replicate assays by 20–99% compared to ordinary fluorescence microscopy.

A photonic crystal (PC) surface is demonstrated as a high-sensitivity platform for detection of a panel of 21 cancer biomarker antigens using a sandwich enzyme-linked immunosorbent assay (ELISA) microarray format. A quartz-based PC structure fabricated by nanoimprint lithography, selected for its low autofluorescence, supports two independent optical resonances that simultaneously enable enhancement of fluorescence detection of biomarkers and label-free quantification of the density of antibody capture spots. A detection instrument is demonstrated that supports fluorescence and label-free imaging modalities, with the ability to optimize the fluorescence enhancement factor on a pixel-by-pixel basis throughout the microarray using an angle-scanning approach for the excitation laser that automatically compensates for variability in surface chemistry density and capture spot density. Measurements show that the angle-scanning illumination approach reduces the coefficient of variation of replicate assays by 20-99% compared to ordinary fluorescence microscopy, thus supporting reduction in limits of detectable biomarker concentration. Using the PC resonance, biomarkers in mixed samples were detectable at the lowest concentrations tested (2.1-41 pg/mL), resulting in a three-log range of quantitative detection.

A Photonic Crystal (PC) surface fabricated upon a quartz substrate using nanoimprint lithography has been demonstrated to enhance light emission from fluorescent molecules in close proximity to the PC surface. Quartz was selected for its low autofluorescence characteristics compared to polymer-based PCs, improving the detection sensitivity and signal-to-noise ratio (SNR) of PC Enhanced Fluorescence (PCEF). Nanoimprint lithography enables economical fabrication of the subwavelength PCEF surface structure over entire 1x3 in2 quartz slides. The demonstrated PCEF surface supports a transverse magnetic (TM) resonant mode at a wavelength of λ = 632.8 nm and an incident angle of θ = 11°, which amplifies the electric field magnitude experienced by surface-bound fluorophores. Meanwhile, another TM mode at a wavelength of λ = 690 nm and incident angle of θ = 0° efficiently directs the fluorescent emission toward the detection optics. An enhancement factor as high as 7500 × was achieved for the detection of LD-700 dye spin-coated upon the PC, compared to detecting the same material on an unpatterned glass surface. The detection of spotted Alexa-647 labeled polypeptide on the PC exhibits a 330 × SNR improvement. Using dose-response characterization of deposited fluorophore-tagged protein spots, the PCEF surface demonstrated a 140 × lower limit of detection compared to a conventional glass substrate.

A photonic crystal surface is utilized for detection of cancer biomarkers in a fluorescent-tagged protein microarray assay. The results indicates that the detection limit of assays are reduced by up to 90% through resonant illumination.

Photonic Crystal Enhanced Microscopy (PCEM) utilizes the optical resonances of photonic crystal surfaces for label-free biosensor imaging and amplification of fluorescence. We describe the application of PCEM to biomolecular and cell-based assays.

The effect of resonant fluorescent enhancement from a photonic crystal surface upon the fluorescent photobleaching rate of Cyanine-5 labeled protein has been investigated. We show that the enhanced excitation mechanism for photonic crystal enhanced fluorescence, in which the device surface resonantly couples light from an excitation laser, accelerates photobleaching in proportion to the coupling efficiency of the laser to the photonic crystal. We also show that the enhanced extraction mechanism, in which the photonic crystal directs emitted photons approximately normal to the surface, does not play a role in the rate of photobleaching. We show that the photobleaching rate of dye molecules on the photonic crystal surface is accelerated by 30x compared to an ordinary glass surface, but substantial signal gain is still evident, even after extended periods of continuous illumination at the resonant condition.

A polymeric SU8 rib waveguide Bragg grating filterfabricated using reactive ion etching (RIE) and solvent assisted microcontact molding (SAMIM) is presented. SAMIM is one kind of soft lithography. The technique is unique in which that a composite hPDMS/PDMS stamp was used to transfer the grating pattern onto an inverted SU8 rib waveguide system. The composite grating stamp can be used repeatedly several times with degradation. Using this stamp and inverter rib waveguide structure, the Bragg grating filter fabrication can be significantly simplified.

In this paper, the design and fabrication of a prism shape optical beam deflector utilizing a thermoplastic electro-optic polymer are presented. Experimental results of deflection angles versus various applied electric fields are investigated.

The paper reports design, fabrication and simulation of a polymeric Bragg grating rib waveguide device using solvent assisted microcontact molding (SAMIM) through a single mold.

In this Letter, we demonstrate that fluorescence detection by using surface-bound fluorescent molecules can be enhanced by coupling the fluorescence emission with dually polarized resonant modes of a photonic crystal (PC) substrate. The PC was fabricated through nanoreplica molding by using a plastic substrate. It was designed such that the transverse magnetic (TM)- and transverse electric (TE)-polarized resonance coincided at a specific combination of the incident angle and the illumination wavelength. During excitation, the nonpolarized emission from cyanine-5 was simultaneously coupled with the TE and TM resonant modes and reradiated into the detection instrument, increasing the fluorescence collection efficiency and thus, enhancing the fluorescence detection.