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Multichannel 65 zF rms Resolution CMOS Monolithic Capacitive Sensor for Counting Single Micrometer-Sized Airborne Particles on Chip
Get PDFThe first integrated CMOS monolithic sensor system for on-chip capacitive detection of micrometric airborne particulate matter (PM) is presented. The chip is based on a 32 channel lock-in architecture allowing a dust collection area of 1.15 mm2 where interdigitated differential microelectrodes, fabricated with the top metal and directly exposed to air, allow single particle sensitivity. The preamplifier input capacitance is significantly minimized thanks to the electrode-amplifier proximity and proper partitioning of the sensing area, in order to reduce the noise. Each channel comprises a charge preamplifier with adjustable high-pass filtering for flicker noise shaping, square-wave mixer, gm-C tunable low-pass filter (40-750 Hz), and a 6 bit digital network for automatic compensation of electrodes mismatching with a granularity of 150 aF. Thanks to the capacitive noise of only 65 zF rms with 25 ms temporal resolution, deposition events of single mineral talc particles were recorded down to 1μm diameter with a signal-to-noise ratio of 18dB. This chip paves the way to pervasive mapping of both indoor and outdoor PM in the 1-30 μm range
28.7 CMOS monolithic airborne-particulate-matter detector based on 32 capacitive sensors with a resolution of 65zF rms
No full textThe adverse impact on human health of the exposure to airborne particulate matter (PM) is well known [1]. Although optical and gravimetric instruments are available to detect PM, they lack portability, have poor potential for miniaturization, and are not low cost. Instead, a better spatio-temporal resolution in PM monitoring by means of portable networked sensors would allow significant enhancements in terms of modeling and prediction capabilities and elucidation of subtle toxicological pathways [2]
Non-invasive monitoring of mode-division multiplexed channels on a silicon photonic chip
Get PDFWe demonstrate on-chip non-invasive monitoring of orthogonal modes transmitted in a silicon photonic waveguide. The proposed technique exploits a recently developed ContactLess Integrated Photonic Probe (CLIPP) realizing a fully transparent integrated light detector. The optical intensity of the modes propagating in the waveguide is tracked in time by the CLIPP, with no signal quality degradation induced by monitoring operations. We exploit this concept for the simultaneous monitoring of two intensity modulated 10 Gbit/s data channels transmitted at the same wavelength and multiplexed on the fundamental transverse electric and magnetic modes of the silicon waveguide. By labeling each signal with a weakly modulated pilot tone, the CLIPP can discriminate at the same time the two channels, the monitoring of one signal not affecting the readout of the other one. The scalability of the presented technique to several modes on arbitrary polarization states, along with the fabrication simplicity and CMOS compatibility of the CLIPP detector, makes this approach promising for the monitoring and control of integrated components for mode-division multiplexing systems
Transparent monitoring of light in integrated optics
No full textWe demonstrate transparent monitoring of light in photonic integrated circuits, based on silicon and indium phosphide platforms, by means of a novel integrated photonic probe. In silicon waveguides our transparent probe enables light observation over 30 dB dynamic range, down to -20 dBm sensitivity, and on a microsecond time scale. Application to the tuning of the resonant wavelength of a silicon microring resonator is shown
Integrated Circuit for Subnanosecond Gating of InGaAs/InP SPAD
Get PDFWe present a novel integrated circuit for subnanosecond gating of InGaAs/InP single-photon avalanche diodes (SPADs). It enables the detector in well-defined time intervals (down to 500 ps) and strongly reduces the afterpulsing effect. It includes a fast pulser with rising/falling edge shorter than 300 ps (20%-80%), a wideband comparator and hold-off logic circuitry. The fast avalanche quenching reduces the charge flow in the SPAD, thus decreasing the afterpulsing, a detrimental effect that limits the maximum count rate of InGaAs/InP SPADs. The wideband SiGe comparator guarantees very low timing jitter of the acquired waveforms: <100 ps (FWHM) at 5 V excess bias voltage, when operated with InGaAs/InP SPAD, whereas we estimate that the time jitter of the circuit is < 30 ps
Single-chip CMOS capacitive sensor for ubiquitous dust detection and granulometry with sub-micrometric resolution
No full textA monolithic CMOS chip able to count single airborne particles down to a diameter of 1 Âμm is presented. This mm-sized ASIC addresses the growing need for portable and miniaturized solid-state sensors monitoring air quality to be disseminated in the environment within pervasive wireless sensors networks. Particle counting and sizing are based on high-resolution capacitive detection. State-of-the-art performances (65 zF resolution with 40 Hz bandwidth) are enabled by the combination on the same chip of interdigitated microelectrodes (separated by 1 Âμm distance, matched with the particle size), and ultra-low-noise electronics connected to them achieving the lowest possible parasitic input capacitance. Chip design and characterization are illustrated
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