Using an oblique incident laser beam to measure the optical properties of stomach mucosa/submucosa tissue

<p>Abstract</p> <p>Background</p> <p>The purpose of the study is to determine the optical properties and their differences for normal human stomach mucosa/submucosa tissue in the cardiac orifice <it>in vitro </it>at 635, 730, 808, 890 and 980 nm wavelengths of laser.</p> <p>Methods</p> <p>The measurements were performed using a CCD detector, and the optical properties were assessed from the measurements using the spatially resolved reflectance, and nonlinear fitting of diffusion equation.</p> <p>Results</p> <p>The results of measurement showed that the absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at five different wavelengths vary with a change of wavelength. The maximum absorption coefficient for tissue samples is 0.265 mm^-1at 980 nm, and the minimum absorption coefficient is 0.0332 mm^-1at 730 nm, and the maximum difference in the absorption coefficients is 698% between 730 and 980 nm, and the minimum difference is 1.61% between 635 and 808 nm. The maximum reduced scattering coefficient for tissue samples is 1.19 mm^-1at 635 nm, and the minimum reduced scattering coefficient is 0.521 mm^-1at 980 nm, and the maximum difference in the reduced scattering coefficients is 128% between 635 and 980 nm, and the minimum difference is 1.15% between 890 and 980 nm. The maximum optical penetration depth for tissue samples is 3.57 mm at 808 nm, and the minimum optical penetration depth is 1.43 mm at 980 nm. The maximum diffusion constant for tissue samples is 0.608 mm at 890 nm, and the minimum diffusion constant is 0.278 mm at 635 nm. The maximum diffuse reflectance is 3.57 mm^-1at 808 nm, and the minimum diffuse reflectance is 1.43 mm^-1at 980 nm. The maximum shift Δx of diffuse reflectance is 1.11 mm^-1at 890 nm, and the minimum shift Δx of diffuse reflectance is 0.507 mm^-1at 635 nm.</p> <p>Conclusion</p> <p>The absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at 635, 730, 808, 890 and 980 nm wavelengths vary with a change of wavelength. There were significant differences in the optical properties for tissue samples at five different wavelengths (<it>P </it>< 0.01).</p

Optics and Quantum Electronics

Contains table of contents on Section 3 and reports on nineteen research projects.Defense Advanced Research Projects Agency Grant F49620-96-0126Joint Services Electronics Program Grant DAAH04-95-1-0038National Science Foundation Grant ECS 94-23737U.S. Air Force - Office of Scientific Research Contract F49620-95-1-0221U.S. Navy - Office of Naval Research Grant N00014-95-1-0715Defense Advanced Research Projects Agency/National Center for Integrated Photonics TechnologyMultidisciplinary Research InitiativeU.S. Air Force - Office of Scientific ResearchNational Science Foundation/MRSECU.S. Navy - Office of Naval Research (MFEL) Contract N00014-91-J-1956National Institutes of Health Grant R01-EY11289U.S. Navy - Office of Naval Research (MFEL) Contract N00014-94-0717Defense Advanced Research Projects Agency Contract N66001-96-C-863

WDM-Enabled Optical RAM at 5 Gb/s Using a Monolithic InP Flip-Flop Chip

We experimentally demonstrate an all-optical static random access memory (RAM) cell using a novel monolithic InP set-reset flip-flop (FF) chip and a single hybridly integrated semiconductor optical amplifier-Mach-Zehnder interferometer (SOA-MZI)-based access gate employing wavelength division multiplexing (WDM) data encoding. The FF device is a 6×2 mm2 InP chip having a 97.8% reduced footprint compared with previous FF devices that were successfully employed in optical RAM setups. Successful and error-free RAM operation is demonstrated at 5 Gb/s for both read and write functionalities, having a power penalty of 4.6 dB for write and 0.5 dB for read operations. The theoretical potential of this memory architecture to allow RAM operation with memory speeds well beyond 40 GHz, in combination with continuously footprint-reducing techniques, could presumably lead to future high-speed all-optical RAM implementations that could potentially alleviate electronic memory bottlenecks and boost computer performance

Monolithically integrated all-optical SOA-based SR Flip-Flop on InP platform

In this paper, we demonstrate for the first time a monolithically integrated InP All-Optical Flip-Flop (FF) based on optical coupled SOA-MZI switches. The experimental proof of principle demonstrated successful error free operation of SR-FF functionality at 5 Gb/s

Optical static RAM cell using a monolithically integrated InP Flip-Flop and wavelength-encoded signals

We experimentally demonstrate successful optical static RAM cell operation with READ/WRITE at 5Gbps and I/O wavelength diversity capabilities. The RAM cell incorporates an integrated SOA-MZI Access Gate and a monolithic InP Flip-Flop with coupled switches

All-optical SR flip-flop based on SOA-MZI switches monolithically integrated on a generic InP platform

At the dawning of the exaflop era, High Performance Computers are foreseen to exploit integrated all-optical elements, to overcome the speed limitations imposed by electronic counterparts. Drawing from the well-known Memory Wall limitation, imposing a performance gap between processor and memory speeds, research has focused on developing ultra-fast latching devices and all-optical memory elements capable of delivering buffering and switching functionalities at unprecedented bit-rates. Following the master-slave configuration of electronic Flip-Flops, coupled SOA-MZI based switches have been theoretically investigated to exceed 40 Gb/s operation, provided a short coupling waveguide. However, this flip-flop architecture has been only hybridly integrated with silica-on-silicon integration technology exhibiting a total footprint of 45x12 mm2 and intra-Flip-Flop coupling waveguide of 2.5cm, limited at 5 Gb/s operation. Monolithic integration offers the possibility to fabricate multiple active and passive photonic components on a single chip at a close proximity towards, bearing promises for fast all-optical memories. Here, we present for the first time a monolithically integrated all-optical SR Flip-Flop with coupled master-slave SOA-MZI switches. The photonic chip is integrated on a 6x2 mm2 die as a part of a multi-project wafer run using library based components of a generic InP platform, fiber-pigtailed and fully packaged on a temperature controlled ceramic submount module with electrical contacts. The intra Flip-Flop coupling waveguide is 5 mm long, reducing the total footprint by two orders of magnitude. Successful flip flop functionality is evaluated at 10 Gb/s with clear open eye diagram, achieving error free operation with a power penalty of 4dB

Optically-Enabled Bloom Filter Label Forwarding Using a Silicon Photonic Switching Matrix

Simplified forwarding schemes relying on Bloom filter (BF)-based labels emerge as a promising approach for coping with the substantial increase in lookup table memory requirements associated with the growing number of end-hosts in DataCenters. In this paper, we present for the first time the successful implementation of a BF-label forwarding scheme over a silicon photonic switch fabric and we demonstrate its functionality with 10 Gb/s data packets that carry BF-encoded labels. The optically enabled BF-label forwarding setup utilizes a Si-based 4 × 4 electro-optic switch directly controlled by an amplifier-less and digital-to-analog-converter-less high speed Field Programmable Gate Array board. The FPGA is responsible for extracting the BF-label from the incoming packets and for carrying out the BF-based forwarding function, determining the appropriate switching state towards conveying incoming packets to the desired output. The use of BF-label forwarding allows for rapid switch reconfiguration avoiding the need for large look-up table updates as the network topology changes and devices are added, removed or simply change physical location. Successful operation for 10 Gb/s data packets has been obtained for a 1 × 4 routing layout. © 1983-2012 IEEE