Abstract-The

In order to address the challenge of increasing data rates, next generation optical communication networks will require the co-integration of electronics and photonics. Heterogeneous integration of these technologies has shown promise, but will eventually become bandwidth limited. Faster monolithic approaches will, therefore, be needed, but monolithic approaches using complementary metal-oxide-semiconductor (CMOS) electronics and silicon photonics are typically limited by their underlying electronic or photonic technologies. Here, we report a monolithically integrated electro-optical transmitter that can achieve symbol rates beyond 100 GBd. Our approach combines advanced bipolar CMOS with silicon plasmonics, and addresses key challenges in monolithic integration through the co-design of the electronic and plasmonic layers, including thermal design, packaging, and a nonlinear organic electro-optic material. To illustrate the potential of our technology, we develop two modulator conceptsan ultra-compact plasmonic modulator and, alternatively, a silicon-plasmonic modulator with photonic routing -both directly processed onto the bipolar CMOS electronics.

We report on the development of a flexible 2D optical fiber-based pressure sensing surface suitable for biomedical applications. The sensor comprises of highly-sensitive Fiber Bragg Grating elements embedded in a thin polymer sheet to form a 2x2 cm(2) sensing pad with a minimal thickness of 2.5mm, while it is easily expandable in order to be used as a building block for larger surface sensors. The fabricated pad sensor was combined with a low physical dimension commercially available interrogation unit to enhance the portability features of the complete sensing system. Sensor mechanical properties allow for matching human skin behavior, while its operational performance exhibited a maximum fractional pressure sensitivity of 12 MPa(-1) with a spatial resolution of 1x1cm(2) and demonstrated no hysteresis and real time operation. These attractive operational and mechanical properties meet the requirements of various biomedical applications with respect to human skin pressure measurements, including amputee sockets, shoe sensors, wearable sensors, wheelchair seating-system sensors, hospital-bed monitoring sensors.

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We present a new optical biosensing integration approach with multifunctional capabilities using plasmonic and photonic components on the same chip and a new methodology to design interferometric biosensors exhibiting record high sensitivity and enhanced resolution relying on a planar surface plasmon polariton (SPP) waveguide. First, we use this approach to demonstrate a proof of concept integrated plasmo-photonic liquid refractive index sensor based on a silicon nitride (Si 3 N 4 ) Mach− Zehnder Interferometer (MZI). A 70 μm long, gold metal stripe is incorporated in the sensing arm serving as the transducer element. A variable optical attenuator and a thermo-optic phase shifter are deployed in the Si 3 N 4 reference arm for performance optimization. The variable optical attenuator stage targets high extinction ratio of the resonance at the interferometer output by balancing the power between the two arms whereas the phase shifter is used to tune the MZI at the desired spectral window. Experimental results matched well with numerical simulations showing bulk sensitivity up to 1930 nm/RIU and a resonance extinction ratio of 37 dB. We also provide a theoretical analysis for correlating the sensitivity performance of the sensor with its free spectral range (FSR). Based on this analysis, we propose optimized sensor designs and show that, by engineering the free spectral range of the sensor in the range of 600 nm, sensitivity may be boosted up to 60000 nm/RIU.

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We present a novel Client-Weighted Medium-Transparent MAC (CW-MT-MAC) protocol with enhanced fairness service delivery properties accompanied by a low-loss Remote Access Unit (RAU) architecture for use in indoor, Gbps capable, 60 GHz Radio-over-Fiber (RoF) Wireless Local Access Networks (WLANs). Our approach relies on incorporating a Client Weighted Algorithm (CWA) in the optical capacity allocation mechanism employed in the MT-MAC scheme, so as to distribute the available wavelengths to the different antenna units according to the total number of active users served by each individual antenna. The protocol's throughput and delay fairness characteristics are evaluated and validated through both simulations and analytic modeling for saturated network traffic operational conditions. In addition, extended simulation-based performance analysis for nonsaturated network conditions and for different enduser distributions, traffic loads and available optical wavelengths at 1 Gbps data rates are presented. Our results confirm that complete throughput equalization can be achieved even for highly varying user population patterns when certain wavelength availability conditions are satisfied. At the same time, the presented scheme manages to equalize the average packet delays amongst packets generated by all RAUs while concurrently dropping the Packet Delay Variation (PDV) metric that is essential for Quality of Service (QoS) delivery. Finally the Manuscript received October 9, 2001.

Dielectric loaded surface plasmon waveguides (DLSPPWs) comprised of polymer ridges deposited on top of CMOS compatible metal thin films are investigated at telecom wavelengths. We perform a direct comparison of the properties of copper (Cu), aluminum (Al), titanium nitride (TiN) and gold (Au) based waveguides by implementing the same plasmonic waveguiding configuration for each metal. The DLSPPWs are characterized by leakage radiation microscopy and a fiber-to-fiber configuration mimicking the cut-back method. We introduce the ohmic loss rate (OLR) to analyze quantitatively the properties of the CMOS metal based DLSPPWs relative to the corresponding Au based waveguides. We show that the Cu, Al and TiN based waveguides feature extra ohmic loss compared to Au of 0.027 dB/μm, 0.18 dB/μm and 0.52 dB/μm at 1550nm respectively. The dielectric function of each metal extracted from ellipsometric spectroscopic measurements is used to model the properties of the DLSP-PWs. We find a fairly good agreement between experimental and modeled DLSPPWs properties except for Al featuring a large surface roughness. Finally, we conclude that TiN based waveguides sustaining intermediate effective index (in the range 1.05-1.25) plasmon modes propagate over very short distances restricting the the use of those modes in practical situations.