Continuous High-Sensitivity and High-Bandwidth Atomic Magnetometer

2020 ◽  
Vol 14 (6) ◽  
Author(s):  
Rujie Li ◽  
Fred N. Baynes ◽  
André N. Luiten ◽  
Christopher Perrella
Keyword(s):  
High Sensitivity ◽  
High Bandwidth

LOW-NOISE AND HIGH-BANDWIDTH 0.8 μm CMOS TRANSIMPEDANCE AMPLIFIER FOR OPTICAL RECEIVER CIRCUIT

2005 ◽  
Vol 14 (02) ◽  
pp. 267-279 ◽  
Author(s):  
M. B. GUERMAZ ◽  
L. BOUZERARA ◽  
H. ESCID ◽  
M. T. BELAROUSSI
Keyword(s):  
Dynamic Range ◽  
Supply Voltage ◽  
High Sensitivity ◽  
Low Noise ◽  
Transimpedance Amplifier ◽  
Power Supply Voltage ◽  
Stability Performance ◽  
High Bandwidth ◽  
The Stability ◽  
Transmission Speed

This paper describes and analyzes a low-noise and high-bandwidth transimpedance amplifier featuring a large dynamic range. The designed amplifier is configured on three identical stages that use an active load compensated by an active resistor to improve the stability performance of the amplifier. This topology displays a transimpedance gain of 150 kΩ, which is necessary to obtain a high sensitivity. This structure operates at 5 V power supply voltage, exhibits a gain bandwidth product of 18 THzΩ and a low-noise level of about [Formula: see text]. This transimpedance amplifier can reach a transmission speed of 240 Mb/s for a photocurrent of 0.5 μA. For a photocurrent of 9.5 μA, a transmission speed of 622 Mb/s can be achieved by using an optical fiber connection containing four channels. The predicted performance is verified by simulations using PSPICE and MAGIC tools with 0.8 μm CMOS AMS parameters.

scholarly journals Constant Temperature Anemometer with Self-Calibration Closed Loop Circuit

2020 ◽  
Vol 10 (10) ◽  
pp. 3405
Author(s):  
Jamel Nebhen ◽  
Khaled Alnowaiser ◽  
Sofiene Mansouri
Keyword(s):  
Constant Temperature ◽  
Dynamic Range ◽  
Stress Measurement ◽  
Supply Voltage ◽  
High Sensitivity ◽  
Airflow Rate ◽  
Micro Electro Mechanical Systems ◽  
Calorimetric Sensor ◽  
High Bandwidth ◽  
Constant Temperature Anemometer

In this paper, a Micro-Electro-Mechanical Systems (MEMS) calorimetric sensor with its measurement electronics is designed, fabricated, and tested. The idea is to apply a configurable voltage to the sensitive resistor and measure the current flowing through the heating resistor using a current mirror controlled by an analog feedback loop. In order to cancel the offset and errors of the amplifier, the constant temperature anemometer (CTA) circuit is periodically calibrated. This technique improves the accuracy of the measurement and allows high sensitivity and high bandwidth frequency. The CTA circuit is implemented in a CMOS FD-SOI 28 nm technology. The supply voltage is 1.2 V while the core area is 0.266 mm2. Experimental results demonstrate the feasibility of the MEMS calorimetric sensor for measuring airflow rate. The developed MEMS calorimetric sensor shows a maximum normalized sensitivity of 117 mV/(m/s)/mW with respect to the input heating power and a wide dynamic flow range of 0–26 m/s. The high sensitivity and wide dynamic range achieved by our MEMS flow sensor enable its deployment as a promising sensing node for direct wall shear stress measurement applications.

scholarly journals Engineering sensitivity and spectral range of photodetection in van der Waals materials and hybrids

Nano Express ◽  
2021 ◽  
Author(s):  
Shaili Sett ◽  
Aparna Parappurath ◽  
Navkiranjot Kaur Gill ◽  
Neha Chauhan ◽  
Arindam Ghosh
Keyword(s):  
Van Der Waals ◽  
Photon Counting ◽  
High Sensitivity ◽  
High Gain ◽  
Physical Mechanisms ◽  
Temperature Detection ◽  
Recent Developments ◽  
High Bandwidth ◽  
Industrial Standards ◽  
Very High

Abstract Exploration of van der Waals heterostructures in the field of optoelectronics has produced photodetectors with very high bandwidth as well as ultra-high sensitivity. Appropriate engineering of these heterostructures allows us to exploit multiple light-to-electricity conversion mechanisms, ranging from photovoltaic, photoconductive to photogating processes. These mechanisms manifest in different sensitivity and speed of photoresponse. In addition, integrating graphene-based hybrid structures with photonic platforms provides a high gain-bandwidth product, with bandwidths >> 1 GHz. In this review, we discuss the progression in the field of photodetection in 2D hybrids. We emphasize the physical mechanisms at play in diverse architectures and discuss the origin of enhanced photoresponse in hybrids. Recent developments in 2D photodetectors based on room temperature detection, photon-counting ability, integration with Si and other pressing issues, that need to be addressed for these materials to be integrated with industrial standards have been discussed.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

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