scholarly journals An Instrument for the Characterization and Calibration of Optical Sensors

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5141
Author(s):  
Enrico Gastasini ◽  
Niccolò Capecci ◽  
Francesco Lupi ◽  
Alessio Gagliardi ◽  
Sergio Saponara ◽  
...  

This paper presents the development of a hardware/software system for the characterization of the electronic response of optical (camera) sensors such as matrix and linear color and monochrome Charge Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS). The electronic response of a sensor is required for inspection purposes. It also allows the design and calibration of the integrating device to achieve the desired performance. The proposed instrument equipment fulfills the most recent European Machine Vision Association (EMVA) 1288 standard ver. 3.1: the spatial non uniformity of the illumination ΔE must be under 3%, and the sensor must achieve an f-number of 8.0 concerning the light source. The following main innovations have achieved this: an Ulbricht sphere providing a uniform light distribution (irradiation) of 99.54%; an innovative illuminator with proper positioning of color Light Emitting Diodes (LEDs) and control electronics; and a flexible C# program to analyze the sensor parameters, namely Quantum Efficiency, Overall System Gain, Temporal Dark Noise, Dark Signal Non Uniformity (DSNU1288), Photo Response Non-Uniformity (PRNU1288), Maximum achievable Signal to Noise Ratio (SNRmax), Absolute sensitivity threshold, Saturation Capacity, Dynamic Range, and Dark Current. This new instrument has allowed a camera manufacturer to design, integrate, and inspect numerous devices and camera models (Necta, Celera, and Aria).

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1683
Author(s):  
Winai Jaikla ◽  
Fabian Khateb ◽  
Tomasz Kulej ◽  
Koson Pitaksuttayaprot

This paper proposes the simulated and experimental results of a universal filter using the voltage differencing differential difference amplifier (VDDDA). Unlike the previous complementary metal oxide semiconductor (CMOS) structures of VDDDA that is present in the literature, the present one is compact and simple, owing to the employment of the multiple-input metal oxide semiconductor (MOS) transistor technique. The presented filter employs two VDDDAs, one resistor and two grounded capacitors, and it offers low-pass: LP, band-pass: BP, band-reject: BR, high-pass: HP and all-pass: AP responses with a unity passband voltage gain. The proposed universal voltage mode filter has high input impedances and low output impedance. The natural frequency and bandwidth are orthogonally controlled by using separated transconductance without affecting the passband voltage gain. For a BP filter, the root mean square (RMS) of the equivalent output noise is 46 µV, and the third intermodulation distortion (IMD3) is −49.5 dB for an input signal with a peak-to peak of 600 mV, which results in a dynamic range (DR) of 73.2 dB. The filter was designed and simulated in the Cadence environment using a 0.18-µm CMOS process from Taiwan semiconductor manufacturing company (TSMC). In addition, the experimental results were obtained by using the available commercial components LM13700 and AD830. The simulation results are in agreement with the experimental one that confirmed the advantages of the filter.


Instruments ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 38 ◽  
Author(s):  
Majid Zarghami ◽  
Leonardo Gasparini ◽  
Matteo Perenzoni ◽  
Lucio Pancheri

This paper investigates the use of image sensors based on complementary metal–oxide–semiconductor (CMOS) single-photon avalanche diodes (SPADs) in high dynamic range (HDR) imaging by combining photon counts and timestamps. The proposed method is validated experimentally with an SPAD detector based on a per-pixel time-to-digital converter (TDC) architecture. The detector, featuring 32 × 32 pixels with 44.64-µm pitch, 19.48% fill factor, and time-resolving capability of ~295-ps, was fabricated in a 150-nm CMOS standard technology. At high photon flux densities, the pixel output is saturated when operating in photon-counting mode, thus limiting the DR of this imager. This limitation can be overcome by exploiting the distribution of photon arrival times in each pixel, which shows an exponential behavior with a decay rate dependent on the photon flux level. By fitting the histogram curve with the exponential decay function, the extracted time constant is used to estimate the photon count. This approach achieves 138.7-dB dynamic range within 30-ms of integration time, and can be further extended by using a timestamping mechanism with a higher resolution.


Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3610
Author(s):  
Adrián J. Torregrosa ◽  
Emir Karamehmedović ◽  
Haroldo Maestre ◽  
María Luisa Rico ◽  
Juan Capmany

Up-conversion sensing based on optical heterodyning of an IR (infrared) image with a local oscillator laser wave in a nonlinear optical sum-frequency mixing (SFM) process is a practical solution to circumvent some limitations of IR image sensors in terms of signal-to-noise ratio, speed, resolution, or cooling needs in some demanding applications. In this way, the spectral content of an IR image can become spectrally shifted to the visible/near infrared (VIS/NWIR) and then detected with silicon focal plane arrayed sensors (Si-FPA), such as CCD/CMOS (charge-coupled and complementary metal-oxide-semiconductor devices). This work is an extension of a previous study where we recently introduced this technique in the context of optical communications, in particular in FSOC (free-space optical communications). Herein, we present an image up-conversion system based on a 1064 nm Nd3+: YVO4 solid-state laser with a KTP (potassium titanyl phosphate) nonlinear crystal located intra-cavity where a laser beam at 1550 nm 2D spatially-modulated with a binary Quick Response (QR) code is mixed, giving an up-converted code image at 631 nm that is detected with an Si-based camera. The underlying technology allows for the extension of other IR spectral allocations, construction of compact receivers at low cost, and provides a natural way for increased protection against eavesdropping.


2008 ◽  
Vol 47 (7) ◽  
pp. 5390-5395 ◽  
Author(s):  
Koichi Mizobuchi ◽  
Satoru Adachi ◽  
Jose Tejada ◽  
Hiromichi Oshikubo ◽  
Nana Akahane ◽  
...  

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 76-79
Author(s):  
J. Génin ◽  
R. Charachon

In a multichannel cochlear prosthesis, electrical interactions between electrodes impose severe limitations on dynamic range and selectivity. We present a theoretical model to cope with these limitations. Building a successful cochlear implant requires full custom-integrated circuits. We present the design of such a device, implemented in complementary metal oxide semiconductor technology. The area of the chip is 9 mm2 and it can stimulate 15 cochlear electrodes with current impulses.


Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5572
Author(s):  
Isao Takayanagi ◽  
Ken Miyauchi ◽  
Shunsuke Okura ◽  
Kazuya Mori ◽  
Junichi Nakamura ◽  
...  

In this paper, a prototype complementary metal-oxide-semiconductor (CMOS) image sensor with a 2.8-μm backside-illuminated (BSI) pixel with a lateral overflow integration capacitor (LOFIC) architecture is presented. The pixel was capable of a high conversion gain readout with 160 μV/e− for low light signals while a large full-well capacity of 120 ke− was obtained for high light signals. The combination of LOFIC and the BSI technology allowed for high optical performance without degradation caused by extra devices for the LOFIC structure. The sensor realized a 70% peak quantum efficiency with a normal (no anti-reflection coating) cover glass and a 91% angular response at ±20° incident light. This 2.8-μm pixel is potentially capable of higher than 100 dB dynamic range imaging in a pure single exposure operation.


Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3617 ◽  
Author(s):  
Jasmine Chan ◽  
Zhou Zheng ◽  
Kevan Bell ◽  
Martin Le ◽  
Parsin Haji Reza ◽  
...  

Photoacoustic imaging (PAI) is an emerging imaging technique that bridges the gap between pure optical and acoustic techniques to provide images with optical contrast at the acoustic penetration depth. The two key components that have allowed PAI to attain high-resolution images at deeper penetration depths are the photoacoustic signal generator, which is typically implemented as a pulsed laser and the detector to receive the generated acoustic signals. Many types of acoustic sensors have been explored as a detector for the PAI including Fabry–Perot interferometers (FPIs), micro ring resonators (MRRs), piezoelectric transducers, and capacitive micromachined ultrasound transducers (CMUTs). The fabrication technique of CMUTs has given it an edge over the other detectors. First, CMUTs can be easily fabricated into given shapes and sizes to fit the design specifications. Moreover, they can be made into an array to increase the imaging speed and reduce motion artifacts. With a fabrication technique that is similar to complementary metal-oxide-semiconductor (CMOS), CMUTs can be integrated with electronics to reduce the parasitic capacitance and improve the signal to noise ratio. The numerous benefits of CMUTs have enticed researchers to develop it for various PAI purposes such as photoacoustic computed tomography (PACT) and photoacoustic endoscopy applications. For PACT applications, the main areas of research are in designing two-dimensional array, transparent, and multi-frequency CMUTs. Moving from the table top approach to endoscopes, some of the different configurations that are being investigated are phased and ring arrays. In this paper, an overview of the development of CMUTs for PAI is presented.


Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 375
Author(s):  
Jianwen Li ◽  
Xuan Guo ◽  
Jian Luan ◽  
Danyu Wu ◽  
Lei Zhou ◽  
...  

A 1 GS/s 12-bit pipelined/successive-approximation-register (pipelined/SAR) hybrid analog-to-digital converter (ADC) is presented in this paper, where the five most significant bits are resolved by two cascading 2.5-bit multiplying digital-to-analog converters, and the eight least significant bits are determined by a two-channel time-interleaved successive-approximation-register (TI-SAR) quantizer. An integrated input buffer and an operational amplifier with improved voltage efficiency at 1.8 V are adopted to achieve high-linearity stably in wide band for 1 GS/s. By designing a 500 MS/s 8-bit SAR quantizer at 1 V, the number of required interleaved channels is minimized to simplify the complexity and an adaptive power/ground is used to compensate the common-mode mismatch between the blocks in different power supply voltages. The offset and gain mismatches due to the TI-SAR quantizer are compensated by a calibration scheme based on virtually-interleaved channels. This ADC is fabricated in a 40 nm complementary metal-oxide-semiconductor (CMOS) technology, and it achieves a signal-to-noise-and-distortion ratio (SNDR) of 58.2 dB and a spurious free dynamic range (SFDR) of 72 dB with a 69 MHz input tone. When the input frequency increases to 1814 MHz in the fourth Nyquist zone, it can maintain an SNDR of 55.3 dB and an SFDR of 64 dB. The differential and integral nonlinearities are −0.94/+0.85 least significant bit (LSB) and −3.4/+3.9 LSB, respectively. The core ADC consumes 94 mW, occupies an active area of 0.47 mm × 0.25 mm. The Walden figure of merit reaches 0.14 pJ/step with a Nyquist input.


Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 15 ◽  
Author(s):  
Shu-Jung Chen ◽  
Yung-Chuan Wu

This paper introduces a thermoelectric-type sensor with a built-in heater as an alternative approach to the measurement of vacuum pressure based on frequency modulation. The proposed sensor is fabricated using the TSMC (Taiwan Semiconductor Manufacturing Company, Hsinchu, Taiwan) 0.35 μm complementary metal-oxide-semiconductor-microelectro-mechanical systems (CMOS–MEMS) process with thermocouples positioned central-symmetrically. The proposed frequency modulation technique involves locking the sensor output signal at a given frequency using a phase-lock-loop (PLL) amplifier to increase the signal-to-noise ratio (SNR) and thereby enhance the sensitivity of vacuum measurements. An improved first harmonic signal detection based on asymmetrical applied heating gives a precise measurement. Following calibration, the output voltage is in good agreement with the calibration values, resulting in an error of 0.25% under pressures between 0.1–10 Torr.


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