Differential Diversity-Embedding Space-Time Block Coding for 2 and 4 Transmit Antennas

Abstract-Diversity-Embedding Space-Time Block Coding (DE-STBC), introduced in [1], enables Unequal Error Protection (UEP) using multiple transmit antennas. Even though these codes do not require channel state information (CSI) at the transmitter, they do need it at the receiver for decoding. A novel differential DE-STBC scheme is proposed in this paper to eliminate the need for channel estimation at the receiver which is especially costly with multiple transmit and receive antennas. Most previously proposed differential schemes in the literature are based on orthogonal STBC and hence are not applicable to the nonorthogonal family of DE-STBC considered in this paper

All-organic and organic-silicon photonic ring micro-resonators

Organic electro-optic materials offer exceptional processability (both from solution and the gas phase) that permit fabrication of flexible and conformal device structures and the integration of organic materials with a wide range of disparate materials. In addition, organic electro-optical materials have fundamental response times that are in the terahertz region, and useable electro-optic coefficients that are approaching 300 pm/V (at telecommunication wavelengths). In addition to fabrication by traditional lithographic methods, multiple devices on a single wafer have been fabricated by soft and nano-imprint lithography. In this presentation, we review the fabrication and performance evaluation of a number of all-organic and organic-silicon photonic ring microresonator devices. Both electrical and thermal tuning of devices, including both single and multiple ring micro-resonators, are demonstrated

All-organic and organic-silicon photonic ring micro-resonators

Organic electro-optic materials offer exceptional processability (both from solution and the gas phase) that permit fabrication of flexible and conformal device structures and the integration of organic materials with a wide range of disparate materials. In addition, organic electro-optical materials have fundamental response times that are in the terahertz region, and useable electro-optic coefficients that are approaching 300 pm/V (at telecommunication wavelengths). In addition to fabrication by traditional lithographic methods, multiple devices on a single wafer have been fabricated by soft and nano-imprint lithography. In this presentation, we review the fabrication and performance evaluation of a number of all-organic and organic-silicon photonic ring microresonator devices. Both electrical and thermal tuning of devices, including both single and multiple ring micro-resonators, are demonstrated

Model Order Reduction of Large Circuits Using Balanced Truncation

A method is introduced for model order reduction of large circuits extracted from layout. The algorithm, which is based on balanced realization, can be used for reducing the order of circuits before circuit-level simulation. In contrast to Padebased algorithms which match the reduced order system with original system in some given frequencies, balanced realization based model algorithms provide a nearly optimal matching over all frequencies. Hence the balanced realization method produces stable and more accurate results compared to the Pade-based algorithms for model reduction. In addition given an upper bound for error, it is possible to compute the minimum degree for the reduced order model a priori. A numerically efficient method for balanced truncation of large circuits using the Arnoldi algorithm is presented and experimental results are reported

Submicron optical waveguides and microring resonators fabricated by selective oxidation of tantalum

Submicron tantalum pentoxide ridge and channel optical waveguides and microring resonators are demonstrated on silicon substrates by selective oxidation of the refractory metal, tantalum. The novel method eliminates the surface roughness problem normally introduced during dry etching of waveguide sidewalls and also simplifies fabrication of directional couplers. It is shown that the measured propagation loss is independent of the waveguide structure and thereby limited by the material loss of tantalum pentoxide in waveguides core regions. The achieved microring resonators have cross-sectional dimensions of similar to 600 nm x similar to 500 nm, diameters as small as 80 mu m with a quality, Q, factor of 4.5 x 10(4), and a finesse of 120

Micro-Ring Optical Resonators Fabricated By Selective Oxidation Of Refractory Metals (Sorm)

A novel platform for integrated photonic circuits is proposed based on selective oxidation of refractory metals (SORM). Low-loss tantalum pentoxide coupled micro-ring optical resonators and high-index contrast ridge waveguides are demonstrated based on this platform. © 2013 OSA

High-Performance And Linear Thin-Film Lithium Niobate Mach Zehnder Modulators On Silicon Up To 50 Ghz

Compact electro-optical modulators are demonstrated on thin films of lithium niobate on silicon operating up to 50 GHz. The half-wave voltage length product of the high-performance devices is 3.1 V.cm at DC and less than 6.5 V.cm up to 50 GHz. The 3 dB electrical bandwidth is 33 GHz, with an 18 dB extinction ratio. The third-order intermodulation distortion spurious free dynamic range is 97.3 dBHz2/3 at 1 GHz and 92.6 dBHz2/3 at 10 GHz. The performance demonstrated by the thin-film modulators is on par with conventional lithium niobate modulators but with lower drive voltages, smaller device footprints, and potential compatibility for integration with large-scale silicon photonics