Quantum cascade photonic crystal surface emitting injection laser

A surface emitting quantum cascade injection laser is presented. Direct surface emission is obtained by using a 2D photonic-band-gap structure that simultaneously acts as a microcavity. The approach may allow miniaturization and on-chip-integration of the devices

Noiseless nonreciprocity in a parametric active device

Nonreciprocal devices such as circulators and isolators belong to an important class of microwave components employed in applications like the measurement of mesoscopic circuits at cryogenic temperatures. The measurement protocols usually involve an amplification chain which relies on circulators to separate input and output channels and to suppress backaction from different stages on the sample under test. In these devices the usual reciprocal symmetry of circuits is broken by the phenomenon of Faraday rotation based on magnetic materials and fields. However, magnets are averse to on-chip integration, and magnetic fields are deleterious to delicate superconducting devices. Here we present a new proposal combining two stages of parametric modulation emulating the action of a circulator. It is devoid of magnetic components and suitable for on-chip integration. As the design is free of any dissipative elements and based on reversible operation, the device operates noiselessly, giving it an important advantage over other nonreciprocal active devices for quantum information processing applications.Comment: 17 pages, 4 figures + 12 pages Supplementary Informatio

Optofluidic Formaldehyde Sensing: Towards On-Chip Integration

International audienceFormaldehyde (HCHO), a chemical compound used in the fabrication process of a broad range of household products, is present indoors as an airborne pollutant due to its high volatility caused by its low boiling point ( T=−19 °C). Miniaturization of analytical systems towards palm-held devices has the potential to provide more efficient and more sensitive tools for real-time monitoring of this hazardous air pollutant. This work presents the initial steps and results of the prototyping process towards on-chip integration of HCHO sensing, based on the Hantzsch reaction coupled to the fluorescence optical sensing methodology. This challenge was divided into two individually addressed problems: (1) efficient airborne HCHO trapping into a microfluidic context and (2) 3,5–diacetyl-1,4-dihydrolutidine (DDL) molecular sensing in low interrogation volumes. Part (2) was addressed in this paper by proposing, fabricating, and testing a fluorescence detection system based on an ultra-low light Complementary metal-oxide-semiconductor (CMOS) image sensor. Two three-layer fluidic cell configurations (quartz–SU-8–quartz and silicon–SU-8–quartz) were tested, with both possessing a 3.5 µL interrogation volume. Finally, the CMOS-based fluorescence system proved the capability to detect an initial 10 µg/L formaldehyde concentration fully derivatized into DDL for both the quartz and silicon fluidic cells, but with a higher signal-to-noise ratio (SNR) for the silicon fluidic cell ( SNRsilicon=6.1 ) when compared to the quartz fluidic cell ( SNRquartz=4.9 ). The signal intensity enhancement in the silicon fluidic cell was mainly due to the silicon absorption coefficient at the excitation wavelength, a(λabs=420 nm)=5×104 cm−1 , which is approximately five times higher than the absorption coefficient at the fluorescence emission wavelength, a(λem=515 nm)=9.25×103 cm−

Exploring abstract interfaces in system-on-chip integration

Modern mobile devices are marvels of computation. They can encode high defnition video, processing and compressing over 350MB/s of image data in real time. They have no trouble driving displays with as much resolution as a full laptop, and smartphone manufacturers boast of running games with console quality graphics. Mobile devices pack all of this computational power into a 12\ handheld package by integrating a number of specialized hardware accelerators (IP) along with conventional CPU and GPUs in a system on chip (SoC). Unfortunately, creating these specialized systems is becoming increasingly expensive. Since hardware accelerators come from a number of different sources and design cycles, different accelerator blocks will often contain incompatible hardware interfaces. Therefore, a large portion of SoC design cost comes in the form of designers manually interfacing each accelerator into a system. This work includes everything from building custom logic to wire up a block, to developing the drivers and API needed to take advantage of the hardware. My research focuses on generating these interfaces, including the physical hardware used to tie IP blocks into a system and the associated software collateral. Leveraging recent trends such as High Level Synthesis and other hardware generator methodologies, I propose an IP interface abstraction and parameterization designed to describe the interface of most current IP blocks. By encoding this knowledge at a higher level of abstraction, I am able to construct and demonstrate a hardware generator that maps an interface protocol description into synthesizable register transfer language (RTL), and that can automatically create hardware bridges between different interconnect standards. iv To ease the integration of the next generation of IP blocks-blocks that are automatically generated based of of user specification. I propose a set of interface primitives. \hen integrated into an IP generator, these primitives can automatically generate an interface that my interface system can tie to the rest of the system. I also demonstrate how the information stored in these types of primitives can be used to automatically generate a low level software driver that manages access to the IP blocks. Finally, I show how the simulation environment provided with an IP generator can be used to provide a domain appropriate application programming interface (API) to drive the software. Using an image signal processor generator as my platform, I demonstrate the construction of a map between the simulation software and hardware driver that enables a full one-button flow from algorithm development to applications running on specialized hardware within a working system

Microfluidic cartridge with integrated array of amorphous silicon photosensors for chemiluminescence detection of viral DNA

Portable and simple analytical devices based on microfluidics with chemiluminescence detection are particularly attractive for point-of-care applications, offering high detectability and specificity in a simple and miniaturized analytical format. Particularly relevant for infectious disease diagnosis is the ability to sensitively and specifically detect target nucleic acid sequences in biological fluids. To reach the goal of real-life applications for such devices, however, several technological challenges related to full device integration are still to be solved, one key aspect regarding on-chip integration of the chemiluminescence signal detection device. Nowadays, the most promising approach is on-chip integration of thin-film photosensors. We recently proposed a portable cartridge with microwells aligned with an array of hydrogenated amorphous silicon (a-Si:H) photosensors, reaching attomole level limits of detection for different chemiluminescence model reactions. Herein, we explore its applicability and performance for multiplex and quantitative detection of viral DNA. In particular, the cartridge was modified to accommodate microfluidic channels and, upon immobilization of three oligonucleotide probes in different positions along each channel, each specific for a genotype of Parvovirus B19, viral nucleic acid sequences were captured and detected. With this system, taking advantage of oligoprobes specificity, chemiluminescence detectability, and photosensor sensitivity, accurate quantification of target analytes down to 70 pmol L-1 was obtained for each B19 DNA genotype, with high specificity and multiplexing ability. Results confirm the good detection capabilities and assay applicability of the proposed system, prompting the development of innovative portable analytical devices with enhanced sensitivity and multiplexed capabilities

Simple evanescent field sensor for NIR spectroscopy

Near-Infrared (NIR) spectroscopy is a powerful tool for chemical analysis in applications ranging from biomedicine to analysis of food products and textiles [1]. However, molar absorptivities in this spectral region are usually weak, so that high-sensitivity measurement devices are required. Optical waveguides provide for highly sensitive attenuated total reflection (ATR) spectroscopy in a robust mass-producible format, and allow for ultra-small sample volume, due to the 100 nm scale extent of the evanescent field, and the potential for lab-on-chip integration