7 W mid-infrared supercontinuum generation up to 4.7 µm in an indium-fluoride optical fiber pumped by a high-peak power thulium-doped fiber single-oscillator.

In this letter, a high-power supercontinuum (SC) generation is achieved in an InF3 fiber with a maximum all bands output power of 7 W and spectrum extension up to 4.7 µm. An actively Q-switched mode-locked (QML) Tm3+-doped fiber single-oscillator has been used to pump the fluoride fiber. At the average power level of 15 W, the most energetic QML pulse provided by the fiber laser had an energy of 88 µJ and an estimated peak power of 60 kW. To the best of our knowledge, this is the first experimental demonstration of a Watt-level range supercontinuum generation in an InF3 fiber pumped by a single-oscillator laser system.

Dynamics of the level of deterministic chaos associated with gastric electrical uncoupling in dogs.

This study investigated the impact of gastric electrical uncoupling on the dynamics of the level of deterministic chaos in cutaneous gastric electrical signals. Eight-channel electrogastrograms (EGG) were recorded from 16 unconscious dogs. Controlled gastric electrical uncoupling was introduced by circumferentially cutting the whole gastric muscle at two different locations. Three separate 30-min EGG recordings were obtained from each dog in the three different states (basal, after the first cut, and after the second cut). The Lyapunov exponents were calculated from sixteen 6.31-min intervals with 75% overlap obtained from each channel in each state. Inadequate EGG signals from which the Lyapunov exponent could not be reliably calculated were quantitatively discarded. The variance and the standard deviation of the three Lyapunov exponent distributions obtained from each channel were studied, and the mean values were subjected to a Student t-test. In 65.6% of all studied channels, the level of chaos was significantly different (p< 0.01) after the first cut compared to the basal state, but no predominant direction of variation was observed (47. 7% increment vs. 52.5% decrement). After the second cut, 63.6% of the channels studied showed significantly greater Lyapunov exponent compared to the basal state, and 63.1% exhibited significantly greater (p< 0.01) level of chaos compared to the intercut state. The dynamics of the level of deterministic chaos in canine electrogastrograms is highly sensitive to severe gastric electrical uncoupling. Moreover, some channel configurations seem to be more sensitive than others in detecting uncoupling.