scholarly journals High sensitivity photo receiver design

2004 ◽  
Vol 17 (1) ◽  
pp. 121-131
Author(s):  
Zbigniew Bielecki ◽  
Wladyslaw Kolosowski ◽  
Edward Sedek
Keyword(s):  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Low Noise ◽  
Operating Conditions ◽  
Receiver Design ◽  
Signal To Noise ◽  
Optical Detectors ◽  
Noise Ratio ◽  
Photo Receiver

The paper describes low noise preampliers designed for optical detectors Analysis of operating conditions affecting signal-to-noise ratio has been carried out. Each preamplier was carefully optimized to work with particular type of the detector.

scholarly journals CMUT-Based Sensor for Acoustic Emission Application: Experimental and Theoretical Contributions to Sensitivity Optimization

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2042
Author(s):  
Redha Boubenia ◽  
Patrice Le Moal ◽  
Gilles Bourbon ◽  
Emmanuel Ramasso ◽  
Eric Joseph
Keyword(s):  
Signal Processing ◽  
Signal To Noise Ratio ◽  
Ultrasonic Transducer ◽  
Operating Conditions ◽  
Geometrical Parameters ◽  
Signal To Noise ◽  
Coupling Conditions ◽  
Sensor Structure ◽  
Noise Ratio ◽  
Electrical Connections

The paper deals with a capacitive micromachined ultrasonic transducer (CMUT)-based sensor dedicated to the detection of acoustic emissions from damaged structures. This work aims to explore different ways to improve the signal-to-noise ratio and the sensitivity of such sensors focusing on the design and packaging of the sensor, electrical connections, signal processing, coupling conditions, design of the elementary cells and operating conditions. In the first part, the CMUT-R100 sensor prototype is presented and electromechanically characterized. It is mainly composed of a CMUT-chip manufactured using the MUMPS process, including 40 circular 100 µm radius cells and covering a frequency band from 310 kHz to 420 kHz, and work on the packaging, electrical connections and signal processing allowed the signal-to-noise ratio to be increased from 17 dB to 37 dB. In the second part, the sensitivity of the sensor is studied by considering two contributions: the acoustic-mechanical one is dependent on the coupling conditions of the layered sensor structure and the mechanical-electrical one is dependent on the conversion of the mechanical vibration to electrical charges. The acoustic-mechanical sensitivity is experimentally and numerically addressed highlighting the care to be taken in implementation of the silicon chip in the brass housing. Insertion losses of about 50% are experimentally observed on an acoustic test between unpackaged and packaged silicon chip configurations. The mechanical-electrical sensitivity is analytically described leading to a closed-form amplitude of the detected signal under dynamic excitation. Thus, the influence of geometrical parameters, material properties and operating conditions on sensitivity enhancement is clearly established: such as smaller electrostatic air gap, and larger thickness, Young’s modulus and DC bias voltage.

A Carbon-Based DNA Framework Nano–Bio Interface for Biosensing with High Sensitivity and a High Signal-to-Noise Ratio

ACS Sensors ◽  
2020 ◽  
Vol 5 (12) ◽  
pp. 3979-3987
Author(s):  
Jing Su ◽  
Wenhan Liu ◽  
Shixing Chen ◽  
Wangping Deng ◽  
Yanzhi Dou ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Carbon Based

Magnetoelectric Sensors With Directly Integrated Charge Sensitive Readout Circuit—Improved Field Sensitivity and Signal-to-Noise Ratio

2011 ◽  
Vol 11 (10) ◽  
pp. 2260-2265 ◽  
Author(s):  
Zhao Fang ◽  
Ninad Mokhariwale ◽  
Feng Li ◽  
Suman Datta ◽  
Q. M. Zhang
Keyword(s):  
Room Temperature ◽  
Signal To Noise Ratio ◽  
Low Noise ◽  
Magnetic Sensors ◽  
Readout Circuit ◽  
Signal To Noise ◽  
Low Frequencies ◽  
Field Sensitivity ◽  
Piezoelectric Layers ◽  
Noise Ratio

The large magnetoelectric (ME) coupling in the ME laminates makes them attractive for ultrasensitive room temperature magnetic sensors. Here ,we investigate the field sensitivity and signal-to-noise ratio (SNR) of ME laminates, consisting of magnetostrictive and piezoelectric layers (Metglas and piezopolymer PVDF were used as the model system), which are directly integrated with a low noise readout circuit. Both the theoretical analysis and experimental results show that increasing the number of piezoelectric layers can improve the SNR, especially at low frequencies. We also introduce a figure of merit to measure the overall influence of the piezolayer properties on the SNR and show that the newly developed piezoelectric single crystals of PMN-PT and PZN-PT have the promise to achieve a very high SNR and consequently ultra-high sensitivity room temperature magnetic sensors. The results show that the ME coefficients used in early ME composites development works may not be relevant to the SNR. The results also show that enhancing the magnetostrictive coefficient, for example, by employing the flux concentration effect, can lead to enhanced SNR.

scholarly journals Comparing current noise in biological and solid-state nanopores

2019 ◽  
Author(s):  
A. Fragasso ◽  
S. Schmid ◽  
C. Dekker
Keyword(s):  
Solid State ◽  
Single Molecule ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Ionic Current ◽  
Low Noise ◽  
Signal To Noise ◽  
Experimental Conditions ◽  
High Frequencies ◽  
Noise Ratio

AbstractNanopores bear great potential as single-molecule tools for bioanalytical sensing and sequencing, due to their exceptional sensing capabilities, high-throughput, and low cost. The detection principle relies on detecting small differences in the ionic current as biomolecules traverse the nanopore. A major bottleneck for the further progress of this technology is the noise that is present in the ionic current recordings, because it limits the signal-to-noise ratio and thereby the effective time resolution of the experiment. Here, we review the main types of noise at low and high frequencies and discuss the underlying physics. Moreover, we compare biological and solid-state nanopores in terms of the signal-to-noise ratio (SNR), the important figure of merit, by measuring free translocations of a short ssDNA through a selected set of nanopores under typical experimental conditions. We find that SiNx solid-state nanopores provide the highest SNR, due to the large currents at which they can be operated and the relatively low noise at high frequencies. However, the real game-changer for many applications is a controlled slowdown of the translocation speed, which for MspA was shown to increase the SNR >160-fold. Finally, we discuss practical approaches for lowering the noise for optimal experimental performance and further development of the nanopore technology.

A New Accessory for Infrared Emission Spectroscopy Measurements

1986 ◽  
Vol 40 (3) ◽  
pp. 401-405 ◽  
Author(s):  
M. Handke ◽  
N. J. Harrick
Keyword(s):  
Background Radiation ◽  
Signal To Noise Ratio ◽  
Focal Length ◽  
Infrared Emission ◽  
Operating Conditions ◽  
Signal To Noise ◽  
Small Areas ◽  
Area Of Interest ◽  
Ellipsoidal Mirror ◽  
Noise Ratio

The principal problem in measurement of emission IR spectra is the low signal-to-noise ratio resulting from the large background radiation relative to sample emission. One method of increasing the signal is to collect the emitted radiation over a very large solid angle using an ellipsoidal mirror. In this method, placing the sample at the short focal length of the ellipsoid both increases the amount of radiation collected for an improved signal-to-noise ratio as well as facilitates sampling of small areas. For locating the area of interest, a microscope is mounted on the emission accessory. The results of testing this emission accessory under different operating conditions such as different samples, emission angles, temperatures, etc., are presented.

scholarly journals Improving the Signal to Noise Ratio of QTF Preamplifiers Dedicated for QEPAS Applications

2020 ◽  
Vol 10 (12) ◽  
pp. 4105
Author(s):  
Piotr Z. Wieczorek ◽  
Tomasz Starecki ◽  
Frank K. Tittel
Keyword(s):  
Operational Amplifier ◽  
Narrow Band ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Electrical Signal ◽  
Low Noise ◽  
Detection Sensitivity ◽  
Noise Amplitude ◽  
Signal To Noise ◽  
Noise Ratio

The signal-to-noise ratio (SNR) is a major factor that limits the detection sensitivity of quartz-enhanced photoacoustic spectroscopy (QEPAS) sensors. The higher the electrical signal level compared to the noise amplitude is the lower the concentration of gases that can be detected. For this reason the preamplifier circuits used in QEPAS should be optimized for low-frequency narrow-band applications. Moreover, special care should be taken when choosing a particular operational amplifier in either a transimpedance or voltage (differential) configuration. It turns out that depending on the preamp topology different operational amplifier parameters should be carefully considered when a high SNR of the whole QEPAS system is required. In this article we analyzed the influence of the crucial parameters of low-noise operational preamplifiers used in QEPAS applications and show the resulting limitations of transimpedance and voltage configurations.

scholarly journals Single-molecule optical absorption imaging by nanomechanical photothermal sensing

2018 ◽  
Vol 115 (44) ◽  
pp. 11150-11155 ◽  
Author(s):  
Miao-Hsuan Chien ◽  
Mario Brameshuber ◽  
Benedikt K. Rossboth ◽  
Gerhard J. Schütz ◽  
Silvan Schmid
Keyword(s):  
Single Molecule ◽  
Shot Noise ◽  
Signal To Noise Ratio ◽  
Local Heating ◽  
Single Molecules ◽  
High Sensitivity ◽  
Temperature Sensitive ◽  
Signal To Noise ◽  
Promising Alternative ◽  
Noise Ratio

Absorption microscopy is a promising alternative to fluorescence microscopy for single-molecule imaging. So far, molecular absorption has been probed optically via the attenuation of a probing laser or via photothermal effects. The sensitivity of optical probing is not only restricted by background scattering but it is fundamentally limited by laser shot noise, which minimizes the achievable single-molecule signal-to-noise ratio. Here, we present nanomechanical photothermal microscopy, which overcomes the scattering and shot-noise limit by detecting the photothermal heating of the sample directly with a temperature-sensitive substrate. We use nanomechanical silicon nitride drums, whose resonant frequency detunes with local heating. Individual Au nanoparticles with diameters from 10 to 200 nm and single molecules (Atto 633) are scanned with a heating laser with a peak irradiance of 354 ± 45 µW/µm2 using 50× long-working-distance objective. With a stress-optimized drum we reach a sensitivity of 16 fW/Hz1/2 at room temperature, resulting in a single-molecule signal-to-noise ratio of >70. The high sensitivity combined with the inherent wavelength independence of the nanomechanical sensor presents a competitive alternative to established tools for the analysis and localization of nonfluorescent single molecules and nanoparticles.

NQR Studies of Atomic Arrangements and Chemical Bonding in Glasses

1990 ◽  
Vol 45 (3-4) ◽  
pp. 268-272 ◽  
Author(s):  
Donghoon Lee ◽  
S. J. Gravina ◽  
P. J. Bray
Keyword(s):  
Chemical Bonding ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Signal To Noise ◽  
Low Frequencies ◽  
Large N ◽  
Noise Ratio ◽  
Very High

Abstract A very high sensitivity continuous wave NQR spectrometer was developed to detect pure NQR transitions at low frequencies (down to 200 kHz). A signal-to-noise ratio of more than 100 to 1 has been achieved at about 1.36 MHz for crystalline B 2 0 3 . Two large n B responses have been found in vitreous B 2 0 3 (NMR detected only one site) with linewidths of less than 30 kHz. 27 A1 NQR spectra were obtained for OC-A1203 (Corundum), the mineral andalusite (a form of A1203 • Si0 2), and a glass having the composition of anorthite (CaO • A1203 • 2Si0 2).

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