CCD Detection Research Articles

Image scanning microscopy using radially polarized beam with polarization conversion

Image scanning microscopy (ISM), which combines the confocal scanning microscopy (CSM) with fast wide-field CCD detection, has been demonstrated in the fluorescent imaging, achieving both high resolution and signal to noise ratio (SNR). In this paper, we introduce radially polarized beam to ISM for non-fluorescent imaging. Radially polarized beam is applied to obtain a sharper illumination point spread function (PSF), along with a polarization converter to enhance detection PSF. It is found that the lateral resolution of ISM using radially polarized beam with polarization conversion (RPC-ISM) is improved to 0.28λ by a factor of 20%, as compared to traditional CSM. Further, images of complex object structures are simulated based on the complete model of scanning microscopy. Simulation results indicate an enhanced transverse resolution in RPC-ISM, compared with conventional ISM using circularly polarized beam. This technique can be used for label-free imaging such as semiconductor inspection, nano-lithography and so on.

Measuring refractive indices of a uniaxial crystal by structured light with non-uniform correlation.

We introduce an effective method for measuring the refractive indices of a uniaxial crystal based on the independent self-focusing property of non-uniformly correlated beams along the $x$ and $y$ directions. We demonstrate how the positions of the independent foci can be changed by adjusting coherence lengths to determine the characteristic coherence lengths of the beams in a uniaxial crystal, and how this information can be used to determine the refractive indices by relating the propagation characteristics of the beam in free space and in the crystal. Furthermore, it is demonstrated that, by choosing a high beam order, one can reduce the measuring error caused by CCD detection precision. These results present an example of how non-uniformly correlated beams can be used for applications in anisotropic materials.

Laboratory water-window x-ray microscopy

Soft x-ray microscopy in the water window ( ∼ 285 − 535 e V ) is an emerging and unique tool for 2D and 3D imaging of unstained intact cellular samples in their near-native state with few-10-nm detail. However, present microscopes rely on the high x-ray brightness of synchrotron-radiation sources. Having access to water-window microscopy in the home laboratory would increase the impact and extend the applicability of the method. In the present paper, we review three decades of efforts to build laboratory water-window microscopes and conclude that the method is now reaching the maturity to allow biological studies. The instruments as well as their key components are quantitatively and qualitatively compared. We find that the brightness and the reliability of the laboratory source are the most critical parameters, but that the optics as well as the sample preparation also must be optimized to enable high-resolution imaging with adequate exposure times. We then describe the two sister microscopes in Stockholm and Berlin, which allow reliable high-resolution biological imaging with short exposure times of a few tens of seconds in 2D and a few tens of minutes in 3D. They both rely on a liquid-jet laser-plasma source combined with high-reflectivity normal-incidence multilayer condenser optics, high-resolution zone-plate imaging optics, CCD detection, and cryogenic sample handling. Finally, we present several examples of biological imaging demonstrating the unique properties of these instruments.

Mid-infrared upconversion imaging using femtosecond pulses

Mid-infrared (mid-IR) imaging and spectroscopic techniques have been rapidly evolving in recent years, primarily due to a multitude of applications within diverse fields such as biomedical imaging, chemical sensing, and food quality inspection. Mid-IR upconversion detection is a promising tool for exploiting some of these applications. In this paper, various characteristics of mid-IR upconversion imaging in the femtosecond regime are investigated using a 4f imaging setup. A fraction of the 100 fs, 80 MHz output from a Ti:sapphire laser is used to synchronously pump an optical parametric oscillator, generating 200 fs mid-IR pulses tunable across the 2.7–4.0 μm wavelength range. The signal-carrying mid-IR pulses are detected by upconversion with the remaining fraction of the original pump beam inside a bulk LiNbO3 crystal, generating an upconverted field in the visible/near-IR range, enabling silicon-based CCD detection. Using the same pump source for generation and detection ensures temporal overlap of pulses inside the nonlinear crystal used for upconversion, thus resulting in high conversion efficiency even in a single-pass configuration. A theory is developed to calculate relevant acceptance parameters, considering the large spectral bandwidths and the reduced interaction length due to group velocity mismatch, both associated with ultrashort pulses. Furthermore, the resolution of this ultrashort-pulsed upconversion imaging system is described. It is demonstrated that the increase in acceptance bandwidth leads to increased blurring in the upconverted images. The presented theory is consistent with experimental observations.

Laser damage characteristics of indium-tin-oxide film and polyimide film

This report focuses on the damage characteristics of the indium-tin-oxide (ITO) layer and the polyimide (PI) layer, which are two constituent components of a LCD. This investigation is different from the previous study, in which the alignment layer was deposited directly on a glass substrate. The PI alignment layer is pinned on the ITO film to imitate the structure of the LCD as much as possible in our current study. The damage process of the ITO/Glass sample involves melting, vaporization near the laser-induced damage threshold (LIDT), and removal at a higher fluence. However, the damage process of the PI/ITO/Glass sample involves thermally induced plastic deformation, followed by cooling when the irradiation fluence is near the LIDT, and rupture when the irradiation fluence is higher. The LIDTs of the PI/ITO/Glass samples, as determined by the on-line CCD detection technique, are higher than those of the ITO/Glass samples. The favorable mechanical properties of the PI are primarily responsible for this result.

Design and evaluation of a multiplexed angular-scanning surface plasmon resonance system employing line-laser optics and CCD detection in combination with multi-ligand sensor chips

An angle-scanning Kretschmann configuration SPR instrument allowing multiplexed analysis is presented. Laser light was guided through optics that converted the collimated light into a line-shaped beam, which was directed to a prism, illuminating the gold sensor surface over a 1 × 10 mm area. The reflected light was led to a CCD detector providing simultaneous readout of individual analysis spots along the laser line at a selected angle (fixed-angle detection) or in scanning-angle mode (width of 35°). Full SPR curve could be measured every 3.6 s for each illuminated spot on the sensor surface. Two in-house manufactured flow cell designs were used for evaluating multiplexed angular-scanning SPR. The first comprised six parallel channels with the laser line perpendicular to the flow direction in order to allow interrogation of the sensor surface in the six channels. Refractive index changes by varying solution composition, and adsorption of different concentrations of albumin to the sensor surface could be correctly monitored simultaneously in each of the channels. In the second flow-cell design the laser line was coinciding with the flow path, allowing recording of SPR curves along a 10-mm length of the sensor surface. Adsorption of layers of positively and negatively charged polyelectrolytes could be consistently measured for sixteen selected positions along the channel. As a proof of principle, several target proteins were immobilized on different positions along the sensor and the binding of various antibodies with these proteins was monitored simultaneously, showing excellent selectivity and reproducibility for probing antibody-protein interactions in a multiplexed fashion.

The application research on improvement of genetic algorithm in linear CCD detection

When the linear array image sensor (CCD) is used for spot detection, the optimization of the detection signal is usually one of the problems that plague the user. In linear array imaging sensor (CCD) detection applications, optimization of the detection signal is usually one of the problems with the user. Based on the characteristics of linear array CCD detection signal, a genetic algorithm (GA) is established to solve the problem of mathematical model. In this paper, a new adaptive genetic algorithm (IGA) with directional adaptive guidance and adaptive control technology and threshold constraint technology are proposed for the lack of local optimization ability of the standard genetic algorithm (SGA), premature convergence and low accuracy. By applying IGA to the actual detection data, it is proved that IGA has certain advantages in solving the problem of linear CCD detection signal optimization. In the end of this paper, the performance of IGA, SGA and peak finding algorithm (SP) are analyzed and compared, which fully demonstrates the advantages of IGA in solving such problems.

Heterodyne frequency-domain multispectral diffuse optical tomography of breast cancer in the parallel-plane transmission geometry.

The authors introduce a state-of-the-art all-optical clinical diffuse optical tomography (DOT) imaging instrument which collects spatially dense, multispectral, frequency-domain breast data in the parallel-plate geometry. The instrument utilizes a CCD-based heterodyne detection scheme that permits massively parallel detection of diffuse photon density wave amplitude and phase for a large number of source-detector pairs (10(6)). The stand-alone clinical DOT instrument thus offers high spatial resolution with reduced crosstalk between absorption and scattering. Other novel features include a fringe profilometry system for breast boundary segmentation, real-time data normalization, and a patient bed design which permits both axial and sagittal breast measurements. The authors validated the instrument using tissue simulating phantoms with two different chromophore-containing targets and one scattering target. The authors also demonstrated the instrument in a case study breast cancer patient; the reconstructed 3D image of endogenous chromophores and scattering gave tumor localization in agreement with MRI. Imaging with a novel parallel-plate DOT breast imager that employs highly parallel, high-resolution CCD detection in the frequency-domain was demonstrated.

The temperature dependent luminescent decay kinetics of an emissive copper complex in the single crystalline phase using time-gated luminescence microscopy

The temperature dependence of the luminescent lifetime of a single crystal of Cu(I) phenanthroline, [Cu(dmp)(PPh3)2]BF4 (dmp=2,9-dimethyl-1,10-phenanthroline and PPh3=triphenylphosphine), was measured using a fluorescence lifetime imaging microscope utilizing time-gated CCD detection. At all temperatures between 100K and 292K, the single crystals exhibited biexponential luminescent decay as well as non-linear Arrhenius luminescent decay kinetics. Variable temperature single-crystal XRD measurements revealed that the observed behavior is likely not the result of a crystallographic phase transition.

MAGELLAN ADAPTIVE OPTICS FIRST-LIGHT OBSERVATIONS OF THE EXOPLANETβPIC b. II. 3–5μm DIRECT IMAGING WITH MagAO+Clio, AND THE EMPIRICAL BOLOMETRIC LUMINOSITY OF A SELF-LUMINOUS GIANT PLANET

Young giant exoplanets are a unique laboratory for understanding cool, low-gravity atmospheres. A quintessential example is the massive extrasolar planet $\beta$ Pic b, which is 9 AU from and embedded in the debris disk of the young nearby A6V star $\beta$ Pictoris. We observed the system with first light of the Magellan Adaptive Optics (MagAO) system. In Paper I we presented the first CCD detection of this planet with MagAO+VisAO. Here we present four MagAO+Clio images of $\beta$ Pic b at 3.1 $\mu$m, 3.3 $\mu$m, $L^\prime$, and $M^\prime$, including the first observation in the fundamental CH$_4$ band. To remove systematic errors from the spectral energy distribution (SED), we re-calibrate the literature photometry and combine it with our own data, for a total of 22 independent measurements at 16 passbands from 0.99--4.8 $\mu$m. Atmosphere models demonstrate the planet is cloudy but are degenerate in effective temperature and radius. The measured SED now covers $>$80\% of the planet's energy, so we approach the bolometric luminosity empirically. We calculate the luminosity by extending the measured SED with a blackbody and integrating to find log($L_{bol}$/$L_{Sun}$) $= -3.78\pm0.03$. From our bolometric luminosity and an age of 23$\pm$3 Myr, hot-start evolutionary tracks give a mass of 12.7$\pm$0.3 $M_{Jup}$, radius of 1.45$\pm$0.02 $R_{Jup}$, and $T_{eff}$ of 1708$\pm$23 K (model-dependent errors not included). Our empirically-determined luminosity is in agreement with values from atmospheric models (typically $-3.8$ dex), but brighter than values from the field-dwarf bolometric correction (typically $-3.9$ dex), illustrating the limitations in comparing young exoplanets to old brown dwarfs.

A technological research of high temperature float glass thickness un-touch detection based on CCD sensor

The detection of float glass thickness is an important measurement standard to check quality of glass. Float glass production line can produce many kinds of plate glass with different thickness. When changing glass thickness, its stability is not fixed and this causes a huge deal of waste. If chang e data of thickness can be provided in time, not only production cycle is shortened, but also production cost is decreased. We adopt laser trigonometry displacement measure theory to detect glass thickness on-line. According to the features of glass filed detection and CCD sensor detection characteristics, construct a basic sensor detection system. Because the detection system is running in the high temperature environment, we analyses glass vicinity temperature distribution and air refractive index distribution. We aim at CCD detection data in the high-temperature state to have a deep analysis. Detection precision satisfies the expected demand. The technology improves the precision and stability of the detection, increase the glass production quality and cut down the energy consumption.

Hyperfine and Zeeman structure of lines of Bi I

The hyperfine structure (hfs) and Zeeman splitting of 10 lines of Bi I covering the ultraviolet–near-infrared spectral range—359.6, 412.2, 430.9, 449.3, 472.3, 555.2, 613.5, 699.1, 965.7, and 982.8 nm—have been measured. We used a standard spectroscopic technique supported by a sensitive CCD detection system and precise computer analysis. The Zeeman effect studies were performed for the transverse direction of observation and separated π(ΔM=0) and σ(ΔM=±1) components of lines. The magnetic-dipole (A) hfs constants as well as Lande-gJ factors of Bi I were determined for 10 levels: 32588.22, 41124.99, 42940.52, 43912.37, 44865.08, 45915.88, 49460.91, 50599.67, 55424.3, and 56088.2  cm−1.

3D laser ultramicroscopy: A method for nondestructive characterization of micro- and nanoinclusions in high-purity materials for fiber and power optics

This paper describes a 3D laser ultramicroscopy technique and apparatus for the nondestructive characterization of heterophase inclusions in bulk high-purity materials for fiber and power optics. In this technique, the concentration and size of inclusions undetectable by optical microscopy are determined using CCD detection of the light scattered by them in a direction normal to the incident laser beam at wavelengths from 0.63 to 0.98 μm. The detection limit of the technique in terms of inclusion size is n × (10–100) nm, the range of detectable number concentrations is 1–1011 cm−3, and the scan depth in the sample is ∼1 cm. Its performance has been evaluated using test systems. The potential of the technique is illustrated by the dispersion analysis of promising materials for IR fiber-optic applications.

An Integrated Nucleic Acid Extraction Microchip for Real-time PCR Micro Total Analysis

Abstract A real-time polymerase chain reaction (PCR) micro total analysis system (μ-TAS) was constructed by integrating nucleic acid extraction and PCR amplification with real-time fluorescent detection on a same microfluidic chip, allowing fully automated and on-chip analysis. This approach has the advantages such as low sample consumption, fast analysis and simple operation. Micromachining technology was used to fabricate the anodic molds of integrated nucleic acid extraction microfluidic chip. A polydimethylsiloxane (PDMS) substrate with 3D channels was manufactured by a combination of molds and an injection molding method. The glass substrate and the chip were bonded together using a plasma treatment. The μ-TAS included a microfluidic control device by which micro fluidic velocity (0–10 mL min −1 ) could be adjusted, a TEC platform with a precision of temperature control of 0.1 °C, and a CCD detection module. The DNA of human blood was extracted using a silica gel membrane method on the microfluidic chip. The DNA extraction and detection were preset in the μ-TAS. Human blood lysate (20 μL) was loaded into the extraction chamber and then washed at a speed of 2 mL min −1 . DNA and PCR reagents were mixed and then driven into the PCR chamber at a speed of 1 mL min −1 . The reference gene GAPDH in extracted genome DNA was amplified by PCR and verified by melting curve analysis. The results of nucleic acid extraction method on the chip were compared with those obtained using a standard manual centrifuge extraction method. The on-chip PCR amplifications gave obvious amplification curves, with C T values of 25.3 and 26.9 respectively. The melting temperature of all the amplification products was 89.9 °C. The results validated that the chip-based method and corresponding device could realize the extraction, amplification and detection of nucleic acid automatically.

A flow-injection system coupled to a micro-guard cartridge for monitoring a vinification process.

The present paper describes a flow-injection system coupled to a Micro-Guard cartridge and a miniaturized optical CCD detection system used to monitor the sugars (glucose/fructose) and ethanol content during alcoholic fermentation. The carrier stream (mobile phase) is composed of an aqueous sulfuric acid solution. The flow parameters were studied in order to obtain a good resolution and a wide dynamic concentration range, with a good repeatability. The relative standard deviation (RSD) obtained was inferior to 4%, for n = 3. It was possible to achieve a linear range of up to 12 g L(-1) of sugars and up to 2% (v/v) of ethanol with a detection limit of 2.3 g L(-1) and 0.4% (v/v), for sugars and ethanol concentrations, respectively. The proposed system was successfully applied to monitor a vinification process by the quantification of sugars and ethanol, and also in some finished port wines.

Research of Picture Adaptive Processing for Packaging Printing Online Detection

In the process of printing machines increasing and reduction of speed, the image collected from online detection system for different speed of printing needs picture adaptive processing. In this paper, there are two methods put forward to realize above goal. One method is sequential similarity detection algorithms and the other is ratio value. Apply with VC++ programming to realize image matching on the premise of the unique CCD detection equipment. The experiment results show that: sequential similarity algorithm on the premise of printing machine running in low speed, by comparing with threshold to realize variable-speed imaging. The ratio value method can be used for a variety of printing speed and it has high speed, high detection efficiency and wide range of application.

Impact of different confluent fluid streams viscosities on interconnected porous static mixer device

We present both experimental and numerical simulations for a static mixing device that combines two fluids of different viscosities through a porous media. Experimentally, the mixing extent was determined by the CCD detection. We showed that the porous plug dramatically improved the mixer performance. The numerical simulation identified the zones where the mixing was developed in the system as the mixing component mass flow could be plotted. The mixing principally occurred downstream of the porous plug, which initiated a jet flow due to the viscosities contrast of the two fluids. For a better understanding of the impact of porous on mixing we achieved a morphological study from the X-rays' micro-CT-images. It gave the porosity of the porous and showed an anisotropy of the geometry and then on the permeability, which certainly played a part in the mixing performance.

Subwavelength Metal Apertures for Label-Free Detection of Single-Molecules

A central goal in bioanalytics is to determine the concentration of, and interactions between biomolecules. Nanotechnology offers the possibility to perform such analyses in a highly parallel, low cost and miniaturized fashion. Here we report on label-free counting, mobility and volume analysis of single molecules and nanoparticles during their diffusion through a sub-attoliter detection volume, confined by a 100 nm aperture in a thin gold film. A high concentration of small fluorescent molecules renders the aqueous solution in the aperture brightly fluorescent. Non-fluorescent analytes diffusing into the aperture displace the fluorescent molecules in the solution, leading to a decrease of the detected fluorescence signal, while analytes diffusing out of the aperture return the fluorescence level. The resulting fluorescence fluctuations provide direct information on the volume, concentration and mobility of the non-fluorescent analytes through fluctuation analysis in both time and amplitude. In order to fully benefit from the array of holes and its high capacity of parallelization, the device allows wide-field illumination and CCD detection. This arrangement simplifies instrumentation compared to confocal microscopy and opens new possibilities to detect macromolecules and particles of pharmaceutical importance such as viruses.

Extension of Wavelength Range in Absolute Intensity Calibration of Space-Resolved EUV Spectrometer for LHD Diagnostics

A space-resolved extreme ultraviolet (EUV) spectrometer has been upgraded by extending the wavelength range to 30-650 A to explore impurity line emissions existing at shorter and longer wavelength sides. The absolute intensity calibration is implemented for measurement in the extended wavelength based on bremsstrahlung profiles simultaneously measured in EUV and visible ranges. For the purpose a wider entrance slit of 200µm and a wider space-resolved slit of 1.0 mm are adopted to increase the number of photons to the spectrometer. As a result, the bremsstrahlung intensity can be enhanced by order of magnitude. A centrally peaked high-density discharge at ne(0) ≥ 10 14 cm −3 is also used for the accurate calibration. Thus, the calibration becomes possible, even in longer wavelength side at λ ≥ 400 A. The result at shorter wavelength range of 30-90 A shows a flat calibration factor, suggesting sudden changes of holographic grating efficiency and CCD detection efficiency, while the result at longer wavelength side of λ ≥ 400 A shows a simple extension of the previous calibration factor.

Gas-Phase Raman Spectra of s-trans- and s-gauche-1,3-Butadiene and Their Deuterated Isotopologues

The gas-phase Raman spectra of 1,3-butadiene and its 2,3-d(2),1,1,4,4-d(4) and d(6) isotopologues have been recorded using intense (6 W) green laser excitation and sensitive CCD detection. Hundreds of bands have been observed and assigned for each isotopologue. These spectra provide the best data to date for the s-trans conformer and also provide the first direct observation of the gas-phase Raman bands of the s-gauche conformer. Spectra recorded at elevated temperatures up to 250 °C for the d(0) and d(6) species help confirm the assignment of bands for the gauche rotamer. DFT computations were utilized to complement the studies. For the most part, the observed gas-phase gauche bands are in good agreement with previous matrix isolation studies. A best set of frequencies are reported for the fundamentals of the gauche rotamer of the d(0) and d(6) species.