Beat note stabilization in dual-polarization DFB fiber lasers by an optical phase-locked loop.

A fully fibered microwave-optical source at 1.5 µm is studied experimentally. It is shown that the beat note between two orthogonally polarized modes of a distributed-feedback fiber laser can be efficiently stabilized using an optical phase-locked loop.

Free-space active polarimetric imager operating at 1.55 μm by orthogonality breaking sensing.

We report the design and optimization of an active polarimetric imaging demonstrator operating at 1.55 μm that is based on the orthogonality breaking technique. It relies on the use of a fibered dual-frequency dual-polarization source raster scanned over the scene.

Mode-hopping suppression in long Brillouin fiber laser with non-resonant pumping.

We propose a reliable method for stabilizing narrow linewidth Brillouin fiber lasers with non-resonant pumping. Mode-hopping is suppressed by means of a phase-locked loop that locks the pump-Stokes detuning to a local radio-frequency (RF) oscillator. Stable single-mode operation of a 110-m-long Brillouin fiber laser oscillating at 1.

Dual frequency laser with two continuously and widely tunable frequencies for optical referencing of GHz to THz beatnotes.

A dual-frequency 1.55 µm laser for CW low noise microwave, millimeter and sub millimeter wave synthesis is demonstrated, where frequency stabilization is possible on each wavelength independently. The solid state Er:Yb laser output power is 7 mW.

Long-range polarimetric imaging through fog.

We report an experimental implementation of long-range polarimetric imaging through fog over kilometric distance in real field atmospheric conditions. An incoherent polarized light source settled on a telecommunication tower is imaged at a distance of 1.3 km with a snapshot polarimetric camera including a birefringent Wollaston prism, allowing simultaneous acquisition of two images along orthogonal polarization directions.