Compact Charge-coupled Device Research Articles

The ripple-curry amplifier in photonic applications

This paper discusses the new design of a amplifier for the miniature MEMS-type spectrometer. The application problem of the new amplifier was the correct conditioning of the sensor's photoelectric pulses. The processed signal was a sequence of pulses that had variable both frequency and amplitude value. Thus, such a broadband amplifier should have the functionality of automatic gain control. This paper describes the concept of the new circuit, develops its detailed application, and then performs validation tests. Measurement results of the new circuit are discussed in the final section of the paper. Full Text: PDF ReferencesC. Ortolani, Flow Cytometry Today. Detectors and Electronics, (Springer 2022). pp. 97-119, CrossRef D. Maes, L. Reis, S. Poelman, E. Vissers, V. Avramovic, M. Zaknoune, G. Roelkens, S. Lemey, E. Peytavit, B. Kuyken, "High-Speed Photodiodes on Silicon Nitride with a Bandwidth beyond 100 GHz", Conference on Lasers and Electro-Optics, Optica Publishing Group, (2022). CrossRef R. Das, Y. Xie, A.P. Knights, "All-Silicon Low Noise Photonic Frontend For LIDAR Applications", 2022 IEEE Photonics Conference (IPC), IEEE Xplore (2022). CrossRef FEMTO Messtechnik GmbH, Variable Gain Photoreceiver - Fast Optical Power Meter Series OE-200, DirectLink M. Nehir, C. Frank, S. Aßmann, E.P. Achterberg, "Improving Optical Measurements: Non-Linearity Compensation of Compact Charge-Coupled Device (CCD) Spectrometers", Sensors 19(12), 2833 (2019). CrossRef F. Thomas,; R. Petzold, C. Becker, U. Werban, "Application of Low-Cost MEMS Spectrometers for Forest Topsoil Properties Prediction", Sensors 21(11), 3927 (2021). CrossRef M. Muhiyudin, D. Hutson, D. Gibson, E. Waddell, S. Song, S. Ahmadzadeh, "Miniaturised Infrared Spectrophotometer for Low Power Consumption Multi-Gas Sensing", Sensors 20(14), 3843 (2020). CrossRef S. Maruyama, T Hizawa, K. Takahashi, K. Sawada, "Optical-Interferometry-Based CMOS-MEMS Sensor Transduced by Stress-Induced Nanomechanical Deflection", Sensors 18(1), 138 (2018). CrossRef S. Merlo, P. Poma, E. Crisà, D. Faralli, M. Soldo, "Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry", Sensors 17(3), 8 (2017). CrossRef M.S. Wei, F. Xing, B. Li, Z. You, "Investigation of Digital Sun Sensor Technology with an N-Shaped Slit Mask", Sensors 11(10), 9764 (2011). CrossRef Z. Yang, T. Albrow-Owen, W. Cai, T. Hasan, "Miniaturization of optical spectrometers", Science 371, 6528 (2021). CrossRef Hamamatsu Photonics K.K. Fingertip size, ultra-compact spectrometer head integrating MEMS and image sensor technologies. DirectLink Microchip Technology Inc, MCP6291/1R/2/3/4/5 1.0 mA 10 MHz Rail-to-Rail Op Amp, CrossRef Microchip Technology Inc. MCP6021/1R/2/3/4 Rail-to-Rail Input/Output 10 MHz Op Amps, CrossRef

Design of a Nonvacuum-Cooling Compact CCD Camera for Scientific Detection

In this article, a nonvacuum-cooling compact (NVCC) scientific charge-coupled device (CCD) camera is presented that includes low noise clocks, a bias driver circuit, a data acquisition circuit, and a temperature control circuit. Experiments are conducted to test the readout performance of the proposed imaging system. The scheme for generating the CCD clocks and the bias driver circuit through ultralow noise low-dropout regulators is designed. The entire design can operate from −40 °C to 40 °C. The test results of the camera show that the system can run at a maximum readout rate of 5 Mpixels/s. The readout noise of the camera is as low as $9.29\,\, {e}^{-}$ when the readout speed is 500 Kpixels/s. The designed camera is currently used in a 1.2-m telescope system at Delingha Observatory.

Improving Optical Measurements: Non-Linearity Compensation of Compact Charge-Coupled Device (CCD) Spectrometers.

Charge-coupled device (CCD) spectrometers are widely used as detectors in analytical laboratory instruments and as sensors for in situ optical measurements. However, as the applications become more complex, the physical and electronic limits of the CCD spectrometers may restrict their applicability. The errors due to dark currents, temperature variations, and blooming can be readily corrected. However, a correction for uncertainty of integration time and wavelength calibration is typically lacking in most devices, and detector non-linearity may distort the signal by up to 5% for some measurements. Here, we propose a simple correction method to compensate for non-linearity errors in optical measurements where compact CCD spectrometers are used. The results indicate that the error due to the non-linearity of a spectrometer can be reduced from several hundred counts to about 40 counts if the proposed correction function is applied.

Accurate wavelength calibration method for compact CCD spectrometer.

Wavelength calibration is an important step in charge-coupled device (CCD) spectrometers. In this paper, an accurate calibration method is proposed. A model of a line profile spectrum is built at the beginning, followed by noise reduction, bandwidth correction, and automatic peak-seeking treatment. Experimental tests are conducted on the USB4000 spectrometer with a mercury-argon calibration light source. Compared with the traditional method, the results show that this wavelength calibration procedure obtains higher accuracy and the deviations are within 0.1 nm.

Battery-Operated Atomic Emission Analyzer for Waterborne Arsenic Based on Atmospheric Pressure Glow Discharge Excitation Source.

In this paper, a sensitive atomic emission spectrometer (AES) based on a new low power and low argon consumption (<8 W, 100 mL min-1) miniature direct current (dc) atmospheric pressure glow discharge (APGD) plasma (3 mm × 5 mm) excitation source was developed for the determination of arsenic in water samples. In this method, arsenic in water was reduced to AsH3 by hydride generation (HG), which was then transported to the APGD source for excitation and detected by a compact CCD (charge-coupled device) microspectrometer. Different parameters affecting the APGD and the hydride generation reactions were investigated. The detection limit for arsenic with the proposed APGD-AES was 0.25 μg L-1, and the calibration curves were found to be linear up to 3 orders of magnitude. The proposed method was successfully applied to the determination of certified reference material (GBW08605), tap water, pond water, groundwater, and hot spring samples. Measurements from the APGD analyzer showed good agreement with the certified value/values obtained with well-established hydride generation atomic fluorescence spectrometry (HG-AFS). These results suggest that the developed robust, cost-effective, and fast analyzer can be used for field based arsenic determination and may provide an important tool for arsenic contamination and remediation programs.

Validation of spectral sky radiance derived from all-sky camera images – a case study

Abstract. Spectral sky radiance (380–760 nm) is derived from measurements with a hemispherical sky imager (HSI) system. The HSI consists of a commercial compact CCD (charge coupled device) camera equipped with a fish-eye lens and provides hemispherical sky images in three reference bands such as red, green and blue. To obtain the spectral sky radiance from these images, non-linear regression functions for various sky conditions have been derived. The camera-based spectral sky radiance was validated using spectral sky radiance measured with a CCD spectroradiometer. The spectral sky radiance for complete distribution over the hemisphere between both instruments deviates by less than 20% at 500 nm for all sky conditions and for zenith angles less than 80°. The reconstructed spectra of the wavelengths 380–760 nm between both instruments at various directions deviate by less than 20% for all sky conditions.

Measuring high-resolution sky luminance distributions with a CCD camera

We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.

Liquid-Phase Broadband Cavity-Enhanced Absorption Spectroscopy Measurements in a 2 mm Cuvette

A novel implementation of broadband cavity enhanced absorption spectroscopy (BBCEAS) has been used to perform sensitive visible wavelength measurements on liquid-phase solutions in a 2 mm cuvette placed at normal incidence to the cavity mirrors. The overall experimental methodology was simple, low cost, and similar to conventional ultraviolet-visible absorption spectroscopy. The cavity was formed by two concave high reflectivity mirrors. Three mirror sets with nominal reflectivities (R) of R = 0.99, 0.9945, and 0.999 were used. The light source consisted of a high intensity red, green, blue, or white LED. The detector was a compact charge-coupled device (CCD) spectrograph. Measurements were made on the representative analytes, Ho(3+), and the dyes brilliant blue-R, sudan black, and coumarin 334 in appropriate solvents. Cavity enhancement factors (CEF) of up to 104 passes for the high reflectivity mirrors were obtained. The number of passes was limited by relatively high scattering and absorption losses in the cavity, of approximately 1 x 10(-2) per pass. Measurements over a wide wavelength range (420-670 nm) were also obtained in a single experiment with the white LED and the R = 0.99 mirror set for Ho(3+) and sudan black. The sensitivity of the experimental setup could be determined by calculating the minimum detectable change in the absorption coefficient alpha(min). The values ranged from 5.1 x 10(-5) to 1.2 x 10(-3) cm(-1). The limit of detection (LOD) for the strong absorber brilliant blue-R was 620 pM. A linear dynamic range of measurements of concentration over about two orders of magnitude was demonstrated. The overall sensitivity of the experimental setup compared very favorably with previous generally more experimentally complex and expensive liquid-phase cavity studies. Possible improvements to the technique and its applicability as an analytical tool are discussed.

Measurement of regional distribution of atmospheric NO and aerosol particles with flashlight long-path optical monitoring

Abstract We report on an air-pollution monitoring campaign in the urban Kyoto area conducted during December 2003 and January 2004. The method is based on the differential optical absorption spectroscopy (DOAS) using an aviation obstruction light (white flashlight). Three sets of DOAS spectrometers, each consisting of a telescope and a compact charge-coupled device (CCD) spectrometer, were operated to cover the southern part of the city area. Three sites were chosen in the urban Kyoto area, and the average concentrations of NO2 were measured with optical path lengths of 2.7, 4.1, and 7.1 km. The aerosol optical thickness was simultaneously measured for the path length of 2.7 km. It is found that the temporal variations of the retrieved amount of the pollution species agree with each other and they are also consistent with concurrent results of the ground sampling measurements.

Fluorescence detection system for capillary separations utilizing a liquid core waveguide with an optical fibre-coupled compact spectrometer

A fluorescence detection system for capillary liquid separation methods is described. The system is based on a silica capillary coated with a low refractive index fluoropolymer Teflon AF that serves both as a separation channel and as a liquid core waveguide (LCW). A fibre-coupled laser excites separated analytes in a detection point and arising fluorescence is collected at one end of the LCW capillary into the other optical fibre which brings it to a compact charge-coupled device (CCD) array spectrometer installed in a desktop computer. No additional components such as focusing optics or filters are necessary. This system was used for detecting isoelectrically focused fluorescent low-molecular-mass p I (isoelectric point) markers and fluorescein isothiocyanate (FITC) labelled proteins. The ability of the system to acquire fluorescent spectra is also demonstrated.

Target diagnostic technology research and development for the LLNL ICF and HED program (invited)

The National Ignition Facility is operational at Lawrence Livermore National Laboratory (LLNL). The inertial confinement fusion and HED programs at LLNL have formed diagnostic research and development groups to institute improvements outside the charter of core diagnostics. We will present data from instrumentation being developed. A major portion of our work is improvements to detectors and readout systems. We have efforts related to charge-coupled device (CCD) development. Work has been done in collaboration with the University of Arizona to back thin a large format CCD device. We have developed in collaboration with a commercial vendor a large format, compact CCD system. We have coupled large format CCD systems to our optical and x-ray streak cameras leading to improvements in resolution and dynamic range. We will discuss gate width and uniformity improvements to microchannel plate-based framing cameras. We will present data from single shot data link work and discuss technology aimed at improvements of dynamic range for high-speed transient measurements from remote locations.

Characterization of an x-ray framing camera utilizing a charge coupled device or film as recording media

A compact charge coupled device (CCD) camera system has been designed and characterized for use in the six inch manipulator (SIM) at the Nova laser facility. The camera system has been designed to directly replace the 35 mm film packages currently used in SIM-based x-ray imaging diagnostics. The unit’s electronic package has been constructed for small size and high thermal conductivity which reduces the overall camera size and improves its performance when operated within the vacuum environment of the Nova target chamber. Measurements of the x-ray imager’s contrast transfer function (CTF) were made under a variety of operating conditions on a static x-ray Manson source using both the CCD and Kodak T-Max 3200 film as recording media. The CTF data were converted to an equivalent modulation transfer function (MTF). The MTF plots show that the microchannel plate has a uniform response within our measurement accuracy along its strips. In a direction normal to the strip, however, the MTF is reduced due to the slant angle of the pores in the MCP. The measurements show that the CCD camera has a lower MTF response than T-MAX film for all spatial frequencies and configurations measured. However, data obtained from the film exhibited reciprocity failure and border effects that are not observed in the CCD data. Measurements indicate that the signal-to-noise ratio for the CCD data is four to six times larger than that obtained with film and higher photon flux levels were recorded. The CCD-based diagnostic offers immediate access to the data, improved dynamic range, and reduced turnaround time, while eliminating the need for film development, digitization, equipment, and personnel.

A simple, low-cost, versatile charge-coupled device spectrometer for plasma spectroscopy

We have constructed a simple, low-cost charge-coupled device (CCD) spectrometer capable of both high resolution (Δλ⩽0.015 nm) and large bandpass (110 nm with Δλ∼0.3 nm). These two modes of operation provide two broad areas of capability for plasma spectroscopy. The first major application is measurement of emission line broadening; the second is emission line surveys from the ultraviolet to the near infrared. Measurements have been made on a low-temperature plasma produced by a miniature electrostatic plasma source and the high-temperature plasma in the Madison Symmetric Torus reversed-field pinch. The spectrometer is a modified Jarrell–Ash 0.5 m Ebert–Fastie monochromator. Light is coupled into the entrance slit with a fused silica fiber optic bundle. The exposure time (2 ms minimum) is controlled by a fast electro-mechanical shutter. The exit plane detector is a compact and robust CCD detector developed for amateur astronomy by Santa Barbara Instrument Group. The CCD detector is controlled and read out by a Macintosh® computer. This spectrometer is sophisticated enough to serve well in a research laboratory, yet is simple and inexpensive enough to be affordable for instructional use.

A compact CCD color camera system with digital AWB control

A novel signal-processing LSI was successfully developed for a compact CCD (charge coupled device) camera, where incident YRGB signals were converted into desired Y, C-Y signals, filtered, compressed, and automatically white-balanced. In order to realize accurate inner AWB (automatic white-balance) control, some ideas concerning white detection, white reproduction, and control speed were studied and developed with digital circuits. Specifically, digital circuits made a hold function, more accurate white detection, and a variable speed control possible. >