Noise and stability in giant-chirp oscillators mode-locked with a nanotube-based saturable absorber

We compare experimental results showing stable dissipative-soliton solutions exist in mode-locked lasers with ultra-large normal dispersion (as large as 21.5 ps2), with both the analytic framework provided by Haus' master-equation and full numerical simulations. © 2010 Optical Society of America.

The absorption of sound by helmholtz resonators with and without flow

Helmholtz resonators are commonly used as absorbers of incident acoustic power. Theoretical and experimental investigations have been performed in the four cases of no mean flow, grazing mean flow, bias mean flow and a combination of grazing and bias mean flows. In the absence of a mean flow, the absorption coefficient (deflned as the proportion of incident energy absorbed) is a non-linear function of the acoustic pressure and high incident acoustic pressures are required before the absorption becomes signiflcant. In contrast, when there is a mean flow present, either grazing or bias, the absorption is linear and thus absorption coefficient is independent of the magnitude of the acoustic pressure, and absorption is obtained over a wider range of frequencies. Non-linear effects are only discernible very close to resonance and at very-high amplitude. With grazing mean flow, there is the undesirable effect that sound can be generated over a range of frequencies due to the interaction between the unsteadily shed vorticity waves and the downstream edge of the aperture. This production is not observed when there is a bias flow because here the vorticity is shed all around the rim of the aperture and swept away by the mean flow. When there is both a grazing mean flow and a mean bias flow, we flnd that only a small amount of bias mean flow, compared with grazing mean flow, is required to destroy the production of acoustic energy. © 2002 by the author(s). Published by the American Institute of Aeronautics and Astronautics, Inc.

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.