Cheetah: A high frame rate, high resolution SWIR image camera

Neys, Joel; Bentell, Jonas; O'Grady, Matt; Colin, Thierry; Hooylaerts, Peter; Grietens, B.

doi:10.1117/12.799633

Cited by 8 publications

(16 citation statements)

References 4 publications

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“…• They need to exhibit a low dark current: in the order of [1][2][3] e -/sec/pixel • The noise level shall be as low as possible and preferably ≤ 5 erms • The sensitivity of the imager shall be as high as possible.…”

Section: Focal Plane Design Considerationsmentioning

confidence: 99%

“…This interface stage is ideally suited for general purpose imaging or spectroscopy with typical integration times in the range of [10 µsec -100 msec]; then the CTIA yields adjustable sensitivity independent from the detector capacitance; low dark current due to the low detector bias and finally low lag when switching between high and low photon flux situations or vice versa [3][4][5][6].…”

Section: Focal Plane Design Considerationsmentioning

confidence: 99%

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COUGAR: a liquid nitrogen cooled InGaAs camera for astronomy and electro-luminescence

et al. 2014

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A SWIR FPA was designed and manufactured with 640*512 pixels, 20 µm pitch and InGaAs detectors for electroluminescence characterization and astronomical applications in the [0.9 -1.55 µm] range. The FPA is mounted in a liquid nitrogen dewar and is operated by a low noise frontend electronics.One of the biggest problem in designing sensors and cameras for electro-luminescence measurements is the autoillumination of the detectors by the readout circuit. Besides of proper shielding of the detectors, the ROIC shall be optimized for minimal electrical activity during the integration time of the very-weak signals coming from the circuit under test. For this reason a SFD (or Source Follower per Detector) architecture (like in the Hawaii sensor) was selected, resulting in a background limited performance of the detector.The pixel has a (somewhat arbitrary) full well capacity of 400 000 e -and a sensitivity of 2.17 µV/e -.The dark signal is app. 1 e-/pixel/sec and with the appropriate Fowler sampling the dark noise lowers below 5 erms . The power consumption of the circuit is limited 2 mW, allowing more than 24 hours of operation on less than 1 l of liquid nitrogen. The FPA is equipped with 4 outputs (optional readout on one single channel) and is capable of achieving 3 frames per second. Due to the non-destructive readout it is possible to determine in a dynamic way the optimal integration time for each observation.The Cougar camera is equipped with ultra-low noise power supply and bias lines; the electronics contain also a 24 bit AD converter to fully exploit the sensitivity of the FPA and the camera.

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Section: Focal Plane Design Considerationsmentioning

confidence: 99%

Section: Focal Plane Design Considerationsmentioning

confidence: 99%

COUGAR: a liquid nitrogen cooled InGaAs camera for astronomy and electro-luminescence

et al. 2014

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“…For these applications, Xenics developed the Rufus camera (see Figure 1), based on a 640 x 512 pixel resolution FPA for the SWIR (900 to 1700 nm) or VisNIR (400 to 1700 nm) spectral range 5 . The Rufus-640 SWIR camera tackles the challenge to operate during day and night under highly varying conditions.…”

Section: Experimental Environmentmentioning

confidence: 99%

Smart onboard image enhancement algorithms for SWIR day and night vision camera

et al. 2015

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SWIR imaging based on InGaAs based FPAs is well suited for passive or active day and night vision applications in different weather conditions, including surveillance, defense or fire-fighting. Xenics developed the Rufus camera, based on a 640 x 512 pixel resolution FPA. In order to achieve the best performance over a large span of lighting conditions, different smart algorithms are implemented onboard.The auto-exposure algorithm optimizes the integration time in order to position the image histogram at a given usercontrolled brightness level. Moreover the algorithm can also switch automatically between different gain and read-out modes. At the same time a TrueNUC™ algorithm is calculating the non-uniformity correction. This correction depends on the detector temperature and integration time, because of the variable dark current of the InGaAs diodes. After the image correction and auto-exposure, further image enhancement is done by additional auto-gain and histogram equalization algorithms. Depending on the application, the user can modify several parameters of the algorithms, e.g. the maximal allowed stretching, the output histogram position and equalization strength.In the paper we will report on the performance of the algorithms at different environmental conditions. The residual Fixed Pattern Noise (FPN) of the TrueNUC™ model is analyzed. For the TrueNUC™ implementation a typical residual FPN of <1% is obtained (at 25°C) over the complete integration time range from 100us up to 40ms, both in high and low gain. Finally we will illustrate the capabilities of the algorithms in different applications.

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“…This IR camera is capable of frame rates of up to 200kHz (1.7 kHz full frame), which allows sufficiently high sampling rate to resolve neuronal action potentials. The CMOS readout circuit contains 327,680 capacitive transimpedance amplifiers with small feedback capacitances (7 fF, Neys et al, 2008). In the IR camera, the readout circuit is connected to photodiode layer using Indium bump bonding (Vermeiren et al, 2009).…”

Section: Electronicsmentioning

confidence: 99%

“…Blue pseudo-coloured areas denote the active Pt recording sites. (B) Commercial IR sensors provide another class of high pixel-count CMOS amplifier array, capable of sampling from >10 5 pixels at rates of several kHz (here: Xenics Cheetah 640CL, Neys et al, 2008). Blue pseudocolour in the SEM image indicates Indium bumps on the amplifier input sites.…”

Section: Connecting Bundle and Chipmentioning

confidence: 99%

CHIME: CMOS-hosted in-vivo microelectrodes for massively scalable neuronal recordings

Kollo

Racz

Hanna

et al. 2019

Preprint

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SummaryMammalian brains consist of 10s of millions to 100s of billions of neurons operating at millisecond time scales, of which current recording techniques only capture a tiny fraction. Recording techniques capable of sampling neural activity at such temporal resolution have been difficult to scale: The most intensively studied mammalian neuronal networks, such as the neocortex, show layered architecture, where the optimal recording technology samples densely over large areas. However, the need for application-specific designs as well as the mismatch between the threedimensional architecture of the brain and largely two-dimensional microfabrication techniques profoundly limits both neurophysiological research and neural prosthetics.Here, we propose a novel strategy for scalable neuronal recording by combining bundles of glass-ensheathed microwires with large-scale amplifier arrays derived from commercial CMOS of in-vitro MEA systems or high-speed infrared cameras. High signal-to-noise ratio (<20 μV RMS noise floor, SNR up to 25) is achieved due to the high conductivity of core metals in glass-ensheathed microwires allowing for ultrathin metal cores (down to <1 μm) and negligible stray capacitance. Multi-step electrochemical modification of the tip enables ultra-low access impedance with minimal geometric area and largely independent of core diameter. We show that microwire size can be reduced to virtually eliminate damage to the blood-brain-barrier upon insertion and demonstrate that microwire arrays can stably record single unit activity.Combining microwire bundles and CMOS arrays allows for a highly scalable neuronal recording approach, linking the progress of electrical neuronal recording to the rapid scaling of silicon microfabrication. The modular design of the system allows for custom arrangement of recording sites. Our approach of employing bundles of minimally invasive, highly insulated and functionalized microwires to lift a 2-dimensional CMOS architecture into the 3rd dimension can be translated to other CMOS arrays such as electrical stimulation devices.

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Cheetah: A high frame rate, high resolution SWIR image camera

Cited by 8 publications

References 4 publications

COUGAR: a liquid nitrogen cooled InGaAs camera for astronomy and electro-luminescence

COUGAR: a liquid nitrogen cooled InGaAs camera for astronomy and electro-luminescence

Smart onboard image enhancement algorithms for SWIR day and night vision camera

CHIME: CMOS-hosted in-vivo microelectrodes for massively scalable neuronal recordings

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