High-power ultrafast solid-state laser using graphene based saturable absorber

We demonstrate a graphene based saturable absorber mode-locked Nd:YVO4 solid-state laser, generating ~14nJ pulses with ~1W average output power. This shows the potential for high-power pulse generation. © 2011 Optical Society of America.

High-power ultrafast solid-state laser using graphene based saturable absorber

We demonstrate a graphene based saturable absorber mode-locked Nd:YVO4 solid-state laser, generating ~14nJ pulses with ~1W average output power. This shows the potential for high-power pulse generation. © 2011 Optical Society of America.

Double-wall carbon nanotubes for wide-band, ultrafast pulse generation.

We demonstrate wide-band ultrafast optical pulse generation at 1, 1.5, and 2 μm using a single-polymer composite saturable absorber based on double-wall carbon nanotubes (DWNTs). The freestanding optical quality polymer composite is prepared from nanotubes dispersed in water with poly(vinyl alcohol) as the host matrix. The composite is then integrated into ytterbium-, erbium-, and thulium-doped fiber laser cavities. Using this single DWNT-polymer composite, we achieve 4.85 ps, 532 fs, and 1.6 ps mode-locked pulses at 1066, 1559, and 1883 nm, respectively, highlighting the potential of DWNTs for wide-band ultrafast photonics.

Chirp limitation on Mach-Zehnder interferometer ultrafast switching employing semiconductor optical amplifiers

We show for the first time that for a given switching pulse width, the maximum switching speed obtainable from a Mach-Zehnder interferometer employing semiconductor optical amplifiers is strongly dependent on the SOA chirp characteristics. © 2005 Optical Society of America.

Chirp limitation on Mach-Zehnder interferometer ultrafast switching employing semiconductor optical amplifiers

We show for the first time that for a given switching pulse width, the maximum switching speed obtainable from a Mach-Zehnder interferometer employing semiconductor optical amplifiers is strongly dependent on the SOA chirp characteristics. © 2005 Optical Society of America.

Ultrafast non-thermal electron dynamics in single layer graphene

The impulsive optical excitation of carriers in graphene creates an out-of-equilibrium distribution, which thermalizes on an ultrafast timescale [1-4]. This hot Fermi-Dirac (FD) distribution subsequently cools via phonon emission within few hundreds of femtoseconds. While the relaxation mechanisms mediated by phonons have been extensively investigated, the initial stages, ruled by fundamental electron-electron (e-e) interactions still pose a challenge. © 2013 IEEE.

Integrated optically triggered polarisation-switching in InGaAsP twin-stripe injection lasers

A new form of ultrafast bistable polarization switching in twin-stripe injection lasers has been observed. For the first time, triggering between bistable states has been achieved by injecting light from a neighboring laser integrated on the same chip. Ultrafast switching times of 250 ps have been measured (detector limited).

35 GHz passive mode-locking of InGaAs/GaAs quantum dot lasers at 1.3 μm with Fourier-limited pulses

We report 35 GHz passive mode-locking and 20 GHz hybrid mode-locking of quantum dot (QD) lasers at 1.3 μm. Our investigations show ultrafast absorber recovery times and for the first time transform-limited mode-locked pulses. © 2003 Optical Society of America.

Improving the consensus performance via predictive mechanisms

Considering some predictive mechanisms, we show that ultrafast average-consensus can be achieved in networks of interconnected agents. More specifically, by predicting the dynamics of the network several steps ahead and using this information in the design of the consensus protocol of each agent, drastic improvements can be achieved in terms of the speed of consensus convergence, without changing the topology of the network. Moreover, using these predictive mechanisms, the range of sampling periods leading to consensus convergence is greatly expanded compared with the routine consensus protocol. This study provides a mathematical basis for the idea that some predictive mechanisms exist in widely-spread biological swarms, flocks, and networks. From the industrial engineering point of view, inclusion of an efficient predictive mechanism allows for a significant increase in the speed of consensus convergence and also a reduction of the communication energy required to achieve a predefined consensus performance.

21 Port self wavelength switching of 40 Gb/s spectral-amplitude-encoded DPSK signals

Ultrafast self-switching of spectral-amplitude-encoded 40 Gb/s DPSK signals is demonstrated for the first time. Switching between 21 ports with 15nm maximum bin separation is achieved using a single correlator based on HNLF and an AWG. © 2009 IEEE.