Tunable acousto-optic spectral imager for atmospheric composition measurements in the visible spectral domain.

We describe a new spectral imaging instrument using a TeO(2) acousto-optical tunable filter (AOTF) operating in the visible domain (450-900 nm). It allows for fast (~1 second), monochromatic (FWHM ranges from 0.6 nm at 450 nm to 3.

Spontaneous motion of cavity solitons induced by a delayed feedback.

We study the properties of 2D cavity solitons in a coherently driven optical resonator subjected to a delayed feedback. The delay is found to induce a spontaneous motion of a single cavity soliton that is stationary and stable otherwise. This behavior occurs when the product of the delay time and the feedback strength exceeds some critical value.

Secure communication scheme using chaotic laser diodes subject to incoherent optical feedback and incoherent optical injection.

We propose a secure communication scheme based on anticipating synchronization of two chaotic laser diodes, one subject to incoherent optical feedback and the other to incoherent optical injection. This scheme does not require fine tuning of the optical frequencies of both lasers as is the case for other schemes based on chaotic laser diodes subject to coherent optical feedback and injection. Our secure communication scheme is therefore attractive for experimental investigation.

Low-frequency pulsations in class-B solid-state lasers with delayed feedback.

We report on the numerical observation of short-duration low-frequency pulsations in class-B solid-state lasers subject to delayed feedback. The period of these pulsations is much larger than either the delay induced by the feedback or the relaxation oscillation period of the laser without feedback. A link is established between the low-frequency pulsations and the low-frequency fluctuations observed in semiconductor lasers subject to coherent optical feedback.

Low-frequency fluctuations in the Lang-Kobayashi equations.

The Lang-Kobayashi equations are simplified by a local analysis that focuses, in the long-delay-time limit, on one pair of mode-antimode only. In the domain of hysteresis between the two steady states, low frequency fluctuations (LFF) can be observed if there is a domain of bistability where both steady states are unstable. The high-frequency oscillations and the drop-offs in the LFF regime are associated with a dynamics close to the unstable upper and lower branch steady states, respectively.