High-Performance Chip- Assisted Microwave Photonic Functionalities

Integrated microwave photonics (IMWP) is poised to release the bottlenecks in modern wireless communication systems. The manipulation of microwave signals in the optical domain offers key advantages of broad bandwidth, reconfiguration, and fast tuning speeds. However, in current IMWP devices, there are some challenges that need to be overcome. These include the ~1 GHz frequency resolution of the IMWP functionalities, limited by the on-chip photonic functional devices' performance, which has prompted research into on-chip stimulated Brillouin scattering (SBS) to achieve sub-30 MHz signal processing capabilities. Equally important, the performance metrics including the noise figure, dynamic range, and the insertion loss, need to be improved before commercial deployment. While SBS offers significant advantages of high resolution and reconfigurability, there is potential for improved signal-to-noise ratios and, therefore, to obtain a low noise figure. In this letter, we present an overview of recent approaches for achieving high-performance IMWP functionalities, including SBS-induced noise management and the optimized MWP link configurations

High link performance of Brillouin-loss based microwave bandpass photonic filters

We present a high link-performance multi-band microwave photonic filter based on stimulated Brillouin scattering (SBS) loss responses. The bandpass filter response is formed by suppressing the out-of-band signal using multiple broadened SBS loss responses, which avoids introducing additional noise in the passband. The low-noise SBS bandpass filter is implemented in an optimized high-performance MWP link, which enabled the demonstration of filter functionalities with a low noise figure, reconfigurability, and high resolution. A noise figure of 18.9 dB is achieved in the passband with a filter bandwidth of 0.3 GHz at a central frequency of 14 GHz, with a link gain of −13.9 dB and a spurious free dynamic range of 106 dB.Hz2/3. Bandwidth reconfiguration from 0.1 GHz to 1 GHz and multi-bandpass responses are also demonstrated

In situ optofluidic control of reconfigurable photonic crystal cavities

The mobile nature of fluids is fully exploited in planar photonic crystals to not only tune and reconfigure in situ optical microcavities, in a continuous and reversible manner, but also to create "a posteriori" spatially programmable cavities. Both the amount of liquid and the location of the selectively infiltrated area can be accurately controlled either mechanically, using a microfiber manipulator, or optically, using a laser-controlled evaporation and recondensation scheme. The wide applicability is illustrated by tuning a cavity resonance over 50¿nm, adjusting the frequency splitting of an originally degenerate cavity mode, and by freely moving a liquid-induced cavity through dragging a microdroplet

Nonlinear atom optics and bright gap soliton generation in finite optical lattices

We theoretically investigate the transmission dynamics of coherent matter wave pulses across finite optical lattices in both the linear and the nonlinear regimes. The shape and the intensity of the transmitted pulse are found to strongly depend on the parameters of the incident pulse, in particular its velocity and density: a clear physical picture for the main features observed in the numerical simulations is given in terms of the atomic band dispersion in the periodic potential of the optical lattice. Signatures of nonlinear effects due the atom-atom interaction are discussed in detail, such as atom optical limiting and atom optical bistability. For positive scattering lengths, matter waves propagating close to the top of the valence band are shown to be subject to modulational instability. A new scheme for the experimental generation of narrow bright gap solitons from a wide Bose-Einstein condensate is proposed: the modulational instability is seeded in a controlled way starting from the strongly modulated density profile of a standing matter wave and the solitonic nature of the generated pulses is checked from their shape and their collisional properties

Interaction of N solitons in the massive Thirring model and optical gap system: the Complex Toda Chain Model

Using the Karpman-Solov''ev quasiparticle approach for soliton-soliton interaction I show that the train propagation of N well separated solitons of the massive Thirring model is described by the complex Toda chain with N nodes. For the optical gap system a generalised (non-integrable) complex Toda chain is derived for description of the train propagation of well separated gap solitons. These results are in favor of the recently proposed conjecture of universality of the complex Toda chain.Comment: RevTex, 23 pages, no figures. Submitted to Physical Review