1996 IEEE Nuclear Science Symposium. Conference Record, Dec 24, 2002
This work present an analysis of the peculiar characteristics of the front-end electronics for ra... more This work present an analysis of the peculiar characteristics of the front-end electronics for radiation detectors employing bipolar transistors, taking into account the noise, speed and power-dissipation constraints. It is shown that, in a first approximation, the optimum processing time is inversely proportional to the dissipated power P/sub d/ of the front-end stage, while the optimum noise performance can be made almost independent on P/sub d/. The noise characteristics of a bipolar transistor having a maximum cut-off frequency of 8 GHz have been experimentally determined, and discussed in relation with the low-power requirements. A prototype of a charge amplifier operated with a single power supply of 3 Volt and a dissipation of 600 /spl mu/W has been tested and showed a ENC=470 electrons r.m.s. at 10 ns RC-CR shaping and with a total input capacitance of 6 pF.
Nuclear Instruments and Methods in Physics Research, Feb 1, 1992
A new electrode geometry for silicon drift chambers is proposed, minimizing the surface of the de... more A new electrode geometry for silicon drift chambers is proposed, minimizing the surface of the detector covered with oxide, still maintaining a reasonably high drifting field with no limitation in the det ector size. This Letter describes the design criteria and discusses the peculiar trajectory of signal electrons within the device. The proposed detector is particularly suited for fine spectroscopy measurements of visible light of soft X-rays, where radiation is totally absorbed within a few microns from the interface.
This paper describes an experimental setup for spectroscopy measurements based on the digital pro... more This paper describes an experimental setup for spectroscopy measurements based on the digital processing of samples obtained by digitizing the signal pulse as it appears at the output of a proper conditioning circuit. The system shares with conventional pulse-height analysis systems the connection to the detector and the preamplifier, but differs from them as it uses an antialiasing filter and a digitizer instead of a shaper and a multichannel analyzer. The implemented algorithm maximizes the signal-to-noise ratio in the estimate of the amplitude of the signal pulse and represents the digital counterpart of the optimum analog processor stated by the theory of the optimum filtering. The system is able to synthesize the best possible filter through the on line measurement of the noises actually present in the experiment, thus leading to the best resolution and allowing a total flexibility in adapting to changeable noise conditions. The performance of the digital system in terms of resolution is investigated and its count rate capability is mentioned. In particular, an improvement in energy resolution of more than 10% has been experimentally achieved with respect to conventional systems based on analog circuitry. All the components of the system are described and, as an example of application, the energy spectrum of 241Am is acquired and reported.
A charge amplifier, especially designed for FET integrated on silicon radiation detectors, is pre... more A charge amplifier, especially designed for FET integrated on silicon radiation detectors, is presented. The circuit is based on the forward biased FET amplifier configuration, which does not require the feedback resistor nor additional devices for resetting. The severe constraints on the preamplifier design, imposed by the low transconductance of small size integrated FET's, are analyzed as far as loop-gain, bandwidth, and noise are concerned. A circuit topology which satisfies all the requirements even at relatively fast shaping time (1 μs) is proposed and experimentally tested
CIPHER (Coded Imager and Polarimeter for High Energy Radiation) is a hard X and soft gamma-ray sp... more CIPHER (Coded Imager and Polarimeter for High Energy Radiation) is a hard X and soft gamma-ray spectroscopic and polarimetric coded mask telescope based on an array of Cadmium Telluride microspectrometers. The position sensitive detector (PSD) is arranged in 4 modules of 32×32 crystals, each of 2×2 mm2 cross section and 10 mm thickness giving a total active area of about
The criteria underlying the design of low-noise front-end integrated electronics for radiation an... more The criteria underlying the design of low-noise front-end integrated electronics for radiation and particle detectors have been determined, taking into account the limits in the allowable power dissipation. The analysis specifically treats integrated amplifiers employing silicon bipolar transistors, whose performance has been studied to highlight the ultimate noise limit and the roles of the front-end device parameters such as the
We demonstrate a temperature and wavelength shift resilient silicon transmission and routing inte... more We demonstrate a temperature and wavelength shift resilient silicon transmission and routing interconnect system suitable for multi-socket interconnects, utilizing a dual-strategy CLIPP feedback circuitry that safeguards the operating point of the constituent photonic building blocks along the entire on-chip transmission-multiplexing-routing chain. The control circuit leverages a novel control power-independent and calibration-free locking strategy that exploits the 2nd derivative of ring resonator modulators (RMs) transfer function to lock them close to the point of minimum transmission penalty. The system performance was evaluated on an integrated Silicon Photonics 2-socket demonstrator, enforcing control over a chain of RM-MUX-AWGR resonant structures and stressed against thermal and wavelength shift perturbations. The thermal and wavelength stress tests ranged from 27°C to 36°C and 1309.90 nm to 1310.85 nm and revealed average eye diagrams Q-factor values of 5.8 and 5.9 respecti...
A low-noise USB-controlled impedance analyzer specifically designed for light monitoring in photo... more A low-noise USB-controlled impedance analyzer specifically designed for light monitoring in photonic circuits using contactless waveguide conductance detector (CLIPP) is presented. The on-board microcontroller and auxiliary analog output allow the closed-loop control of photonic components.
We report on the use of programmable silicon photonic meshes of thermally tuneable interferometer... more We report on the use of programmable silicon photonic meshes of thermally tuneable interferometers to manipulate dynamically guided-wave and free-space optical beams on a chip through arbitrary linear transformations. Several applications are presented, including automatic reconstruction and unscrambling of mixed optical modes; forming and steering of free-space optical beams; coupling of free-space beams from arbitrary directions of arrival to single-mode waveguides; phase front reconstruction and beaming through scattering media. Automatic self-configuration of the meshes is achieved by exploiting built-in transparent monitors, beam labelling and thermal crosstalk cancellation strategies, enabling scalability to photonic meshes with a large number of interferometers.
Nuclear Instruments and Methods in Physics Research, May 1, 1998
Abstract The paper presents the analog section of a readout electronics for multichannel detector... more Abstract The paper presents the analog section of a readout electronics for multichannel detector systems using VLSI bipolar technology. The charge amplifier and the fast shaper (peaking time 20 ns) are designed for minimum noise (ENC
Exploiting a novel channel labeling scheme, we demonstrate automated tuning and locking of a hitl... more Exploiting a novel channel labeling scheme, we demonstrate automated tuning and locking of a hitless silicon microring-resonator filter. Hitless tuning with more than 30 dB isolation is achieved, enabling application in add-drop reconfigurable architectures.
A mixed-signal electronic system allowing closed-loop control of 16 independent integrated photon... more A mixed-signal electronic system allowing closed-loop control of 16 independent integrated photonic devices equipped with CLIPP transparent optical probes (−35 dBm sensitivity, 50 kHz speed) is presented. It features a 32-channel CMOS lock-in front-end (203 nV /√Hz noise, 100 dB dynamic range), interfaced via conditioning chains to multiple ADCs and DACs driven by a Xilinx Spartan-6 FPGA for real-time processing, including the generation and demodulation of multiple pilot tones for channel labeling and dithering-based feedback. The results of the platform characterization are reported, along with the first application of automatic control applied to a novel all-optical unscrambler for mode-division multiplexing.
1996 IEEE Nuclear Science Symposium. Conference Record, Dec 24, 2002
This work present an analysis of the peculiar characteristics of the front-end electronics for ra... more This work present an analysis of the peculiar characteristics of the front-end electronics for radiation detectors employing bipolar transistors, taking into account the noise, speed and power-dissipation constraints. It is shown that, in a first approximation, the optimum processing time is inversely proportional to the dissipated power P/sub d/ of the front-end stage, while the optimum noise performance can be made almost independent on P/sub d/. The noise characteristics of a bipolar transistor having a maximum cut-off frequency of 8 GHz have been experimentally determined, and discussed in relation with the low-power requirements. A prototype of a charge amplifier operated with a single power supply of 3 Volt and a dissipation of 600 /spl mu/W has been tested and showed a ENC=470 electrons r.m.s. at 10 ns RC-CR shaping and with a total input capacitance of 6 pF.
Nuclear Instruments and Methods in Physics Research, Feb 1, 1992
A new electrode geometry for silicon drift chambers is proposed, minimizing the surface of the de... more A new electrode geometry for silicon drift chambers is proposed, minimizing the surface of the detector covered with oxide, still maintaining a reasonably high drifting field with no limitation in the det ector size. This Letter describes the design criteria and discusses the peculiar trajectory of signal electrons within the device. The proposed detector is particularly suited for fine spectroscopy measurements of visible light of soft X-rays, where radiation is totally absorbed within a few microns from the interface.
This paper describes an experimental setup for spectroscopy measurements based on the digital pro... more This paper describes an experimental setup for spectroscopy measurements based on the digital processing of samples obtained by digitizing the signal pulse as it appears at the output of a proper conditioning circuit. The system shares with conventional pulse-height analysis systems the connection to the detector and the preamplifier, but differs from them as it uses an antialiasing filter and a digitizer instead of a shaper and a multichannel analyzer. The implemented algorithm maximizes the signal-to-noise ratio in the estimate of the amplitude of the signal pulse and represents the digital counterpart of the optimum analog processor stated by the theory of the optimum filtering. The system is able to synthesize the best possible filter through the on line measurement of the noises actually present in the experiment, thus leading to the best resolution and allowing a total flexibility in adapting to changeable noise conditions. The performance of the digital system in terms of resolution is investigated and its count rate capability is mentioned. In particular, an improvement in energy resolution of more than 10% has been experimentally achieved with respect to conventional systems based on analog circuitry. All the components of the system are described and, as an example of application, the energy spectrum of 241Am is acquired and reported.
A charge amplifier, especially designed for FET integrated on silicon radiation detectors, is pre... more A charge amplifier, especially designed for FET integrated on silicon radiation detectors, is presented. The circuit is based on the forward biased FET amplifier configuration, which does not require the feedback resistor nor additional devices for resetting. The severe constraints on the preamplifier design, imposed by the low transconductance of small size integrated FET's, are analyzed as far as loop-gain, bandwidth, and noise are concerned. A circuit topology which satisfies all the requirements even at relatively fast shaping time (1 μs) is proposed and experimentally tested
CIPHER (Coded Imager and Polarimeter for High Energy Radiation) is a hard X and soft gamma-ray sp... more CIPHER (Coded Imager and Polarimeter for High Energy Radiation) is a hard X and soft gamma-ray spectroscopic and polarimetric coded mask telescope based on an array of Cadmium Telluride microspectrometers. The position sensitive detector (PSD) is arranged in 4 modules of 32×32 crystals, each of 2×2 mm2 cross section and 10 mm thickness giving a total active area of about
The criteria underlying the design of low-noise front-end integrated electronics for radiation an... more The criteria underlying the design of low-noise front-end integrated electronics for radiation and particle detectors have been determined, taking into account the limits in the allowable power dissipation. The analysis specifically treats integrated amplifiers employing silicon bipolar transistors, whose performance has been studied to highlight the ultimate noise limit and the roles of the front-end device parameters such as the
We demonstrate a temperature and wavelength shift resilient silicon transmission and routing inte... more We demonstrate a temperature and wavelength shift resilient silicon transmission and routing interconnect system suitable for multi-socket interconnects, utilizing a dual-strategy CLIPP feedback circuitry that safeguards the operating point of the constituent photonic building blocks along the entire on-chip transmission-multiplexing-routing chain. The control circuit leverages a novel control power-independent and calibration-free locking strategy that exploits the 2nd derivative of ring resonator modulators (RMs) transfer function to lock them close to the point of minimum transmission penalty. The system performance was evaluated on an integrated Silicon Photonics 2-socket demonstrator, enforcing control over a chain of RM-MUX-AWGR resonant structures and stressed against thermal and wavelength shift perturbations. The thermal and wavelength stress tests ranged from 27°C to 36°C and 1309.90 nm to 1310.85 nm and revealed average eye diagrams Q-factor values of 5.8 and 5.9 respecti...
A low-noise USB-controlled impedance analyzer specifically designed for light monitoring in photo... more A low-noise USB-controlled impedance analyzer specifically designed for light monitoring in photonic circuits using contactless waveguide conductance detector (CLIPP) is presented. The on-board microcontroller and auxiliary analog output allow the closed-loop control of photonic components.
We report on the use of programmable silicon photonic meshes of thermally tuneable interferometer... more We report on the use of programmable silicon photonic meshes of thermally tuneable interferometers to manipulate dynamically guided-wave and free-space optical beams on a chip through arbitrary linear transformations. Several applications are presented, including automatic reconstruction and unscrambling of mixed optical modes; forming and steering of free-space optical beams; coupling of free-space beams from arbitrary directions of arrival to single-mode waveguides; phase front reconstruction and beaming through scattering media. Automatic self-configuration of the meshes is achieved by exploiting built-in transparent monitors, beam labelling and thermal crosstalk cancellation strategies, enabling scalability to photonic meshes with a large number of interferometers.
Nuclear Instruments and Methods in Physics Research, May 1, 1998
Abstract The paper presents the analog section of a readout electronics for multichannel detector... more Abstract The paper presents the analog section of a readout electronics for multichannel detector systems using VLSI bipolar technology. The charge amplifier and the fast shaper (peaking time 20 ns) are designed for minimum noise (ENC
Exploiting a novel channel labeling scheme, we demonstrate automated tuning and locking of a hitl... more Exploiting a novel channel labeling scheme, we demonstrate automated tuning and locking of a hitless silicon microring-resonator filter. Hitless tuning with more than 30 dB isolation is achieved, enabling application in add-drop reconfigurable architectures.
A mixed-signal electronic system allowing closed-loop control of 16 independent integrated photon... more A mixed-signal electronic system allowing closed-loop control of 16 independent integrated photonic devices equipped with CLIPP transparent optical probes (−35 dBm sensitivity, 50 kHz speed) is presented. It features a 32-channel CMOS lock-in front-end (203 nV /√Hz noise, 100 dB dynamic range), interfaced via conditioning chains to multiple ADCs and DACs driven by a Xilinx Spartan-6 FPGA for real-time processing, including the generation and demodulation of multiple pilot tones for channel labeling and dithering-based feedback. The results of the platform characterization are reported, along with the first application of automatic control applied to a novel all-optical unscrambler for mode-division multiplexing.
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