Modern physics experiments often utilize field-programmable gate array (FPGA)-based systems for real-time data acquisition (DAQ). Integrated analog electronics demand for complex calibration ...routines. Furthermore, versatile configuration and control of the whole system are key requirements. Besides a low-level register interface to the FPGA, also, access to I 2 C and SPI buses is often needed to configure the complete system. Calibration through an FPGA is inflexible and yields a complex hardware implementation. On the contrary, calibration through a remote system is possible but considerably slower due to repetitive network accesses. By using system-on-chip (SoC)-FPGA solutions with a microprocessor, more sophisticated configuration and calibration solutions, as well as standard remote access protocols, can be efficiently integrated into the software. Based on Xilinx Zynq US+ SoC-FPGAs, we implemented a versatile control framework. This software framework offers convenient access to the hardware and a flexible abstraction via remote-procedure calls (RPCs). Based on the open-source RPC library gRPC, functionality with low-latency control flow, complex algorithms, data conversions and processing, and configuration via external buses can be provided to a client via Ethernet. Furthermore, client interfaces for various programming languages can be generated automatically, which eases collaboration among different working groups and integration into existing software. This contribution presents the framework and benchmarks regarding latency and data throughput.
This paper reviews the work carried out under the European ACTS KEOPS (KEys to Optical Packet Switching) project, centering on the definition, development and assessment of optical packet switching ...and routing networks capable of providing transparency to the payload bit rate. The adopted approach uses optical packets of fixed duration with low bit rate headers to facilitate processing at the network/node interfaces. The paper concentrates on the networking concepts developed in the KEOPS project through a description of the implementation issues pertinent to optical packet switching nodes and network/node interfacing blocks, and consideration of the network functionalities provided within the optical packet layer. The implementation, from necessity, relies on advanced optoelectronic components specifically developed within the project, which are also briefly described.
Multifiber interconnection technology is one of the important keys to increase package density in optical networks. We present a novel releasable multifiber optical connectivity solution from the ...initial concept to the functional prototypes. This connectivity solution relies on a V-groove alignment platform and a microlens array. It can, e.g., provide reliable connections between a fiber array and an active optoelectronic component array or between a fiber array and an optical waveguide device. Moreover, within a free-space propagation region, it provides access to collimated optical beams, thus enabling various light manipulation options. The microlens V-groove fabrication process makes use of a dedicated assembly station that has been designed for automation. The microlens array is positioned on the platform, aligned relative to the V-grooves, and fixed with a low-cost adhesive bonding technology. Uniform and stable low losses for fiber-to-fiber coupling via two lenses have been achieved for single-mode and multimode fibers at wavelengths of 850, 1300, and 1550 nm. This connectivity solution represents, therefore, a versatile cost-effective technology for releasable connections of fiber arrays to any other optical multiport device
A compact releasable 90deg optical connectivity solution is proposed, realized, and characterized. It can be used for angled interconnection between two small form factor multifiber connectors, or ...between one connector and surface mounted multichannel active optical elements such as vertical-cavity surface-emitting lasers and photodetector arrays. This 90deg connectivity system is based on V-groove substrates and an integrated optical microsystem combining two lens arrays and a 45deg mirror. Realized modules feature average fiber-to-fiber optical losses of 1.4 dB (best below 1 dB) for multimode operation over the whole wavelength range from 850 up to 1550 nm. This interconnect solution provides advantages when limited space is available (e.g., in optical distribution frames, splice closures, high-performance computers)
We describe an advanced InP-InGaAs-based technology for the monolithic integration of pin-photodiodes and SHBT-transistors. Both devices are processed using the same epitaxial grown layer structure. ...Employing this technology, we have designed and fabricated two photoreceivers achieving transimpedance gains of 170 /spl Omega//380 /spl Omega/ and optical/electrical bandwidths of 50 GHz/34 GHz. To the best of our knowledge, this is the highest bandwidth of any heterojunction bipolar transistor (HBT)-based photoreceiver optoelectronic integrated circuit (OEIC) published to date. We even predict a bandwidth of 60 GHz for the same circuit topology by a simple reduction of the photodiode diameter and an adjustment of the feedback resistor value.
A fully packaged 40-Gb/s optical receiver module based on monolithic integration of p-i-n photodiodes and single-heterojunction bipolar transistors (HBT) in the InGaAs-InP material system is ...presented. Combined with an electrical broad-band mounting technique the optical receiver module achieved an overall conversion gain of 48 V/W and showed clearly opened eyes for data rates of 40 Gb/s at a wavelength of 1550 nm.
A chip-on-foil inner-lead bonding process for display driver circuits was analyzed by means of finite-element simulation and experimental validation. The developed model allowed the calculation of ...residual stress as a function of bump arrangement and process parameters. Foil induced shear forces were identified as the root cause of corner bump failures. Simulation based optimization was performed to reduce the shear stresses. A redesign of the chip could eliminate corner bump failures and a reduction of total failure rate after bonding from around 1% to around 100 ppm was achieved.
A compact releasable 90deg optical connectivity solution is proposed, realized, and characterized. It can be used for angled interconnection between two small form factor multifiber connectors, or ...between one connector and surface mounted multichannel active optical elements such as vertical-cavity surface-emitting lasers and photodetector arrays. This 90deg connectivity system is based on V-groove substrates and an integrated optical microsystem combining two lens arrays and a 45deg mirror. Realized modules feature average fiber-to-fiber optical losses of 1.4 dB (best below 1 dB) for multimode operation over the whole wavelength range from 850 up to 1550 nm. This interconnect solution provides advantages when limited space is available (e.g., in optical distribution frames, splice closures, high-performance computers)
High-performance InP/InGaAs double HBTs operating in common-emitter mode with 7.5 W/mm output power density at 10 GHz are reported. A total output power of 600 mW was achieved with five-finger cells ...having total emitter areas of 176 /spl mu/m/sup 2/. Their f/sub T/ and f/sub max/ values are 74 GHz and 89 GHz, respectively. These cells exhibit small-signal maximum stable power gains of 17 dB and Mason's unilateral power gains of 20 dB at 10 GHz.
Low pressure MOVPE growth of layer structures for high performance double hetero bipolar transistors (DHBT) is presented. A very high zinc base doping level of 3.5/spl times/10/sup 19//cm/sup 3/ was ...obtained at a growth temperature of 490/spl deg/C. Zinc outdiffusion was avoided by growth interruptions. The layer structure included a step graded base collector heterojunction. Fabricated DHBT's showed /spl beta/=70, f/sub T/=115 GHz, f/sub max/=170 GHz, and BV/sub CE0/=10 V.
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