A low-coherence continuous wave Doppler Lidar using a synthetic broadband source has been suggested recently. The main advantages are electronically adjustable spatial resolution, strong discrimination between signal contributions from different locations and the enabling of after-measurement numerical range scanning. In this paper an advanced concept is presented with an efficient suppression of unavoidable perturbations from inside the measurement setup.
A range-resolving continuous wave Doppler Lidar is presented based on principles of optical low-coherence re- flectometry (OLCR) and using a source with a bandwidth in the MHz range. As opposed to OLCR the range scanning is not done by changing the length of the reference path in the interferometric setup. Rather, a CW source with synthetic phase noise is used enabling numerical range scanning after each single measurement. The latter feature also is in sharp contrast to conventional CW Lidar. Our concept can be applied to wind sensing as well as to remote vibrometry and differential absorption Lidar.
Some specific aspects of design, fabrication, application and characterization of selected waveguide devices for optical
communication systems will be addressed in this paper ranging from familiar components like Bragg gratings to
emerging devices exploiting stimulated Raman scattering in silicon. In particular, we will focus on fiber-optical and
planar waveguide components for adaptive dispersion compensation, Raman-based amplifying and nonreciprocal
devices in silicon and useful respective characterization techniques.
Waveguide gratings used in laser technology, optical sensing or optical communications have to serve different specific
purposes and, hence, have to have specific optical properties which can be tailored to a large extent. Characterization
methods are required not only to measure the actual effect of a Bragg grating or long period grating under consideration
but also to unveil the cause, i.e. to determine its spatial structure. This paper reviews the present status of the respective
experimental characterization techniques. The methods emphasized rely on phase sensitive reflectometry together with
advanced inverse scattering evaluation algorithms.
Polarization mode dispersion (PMD), polarization dependent loss (PDL) and chromatic dispersion (CD) of fiber optic components and fiber transmission links are key issues in fiber optical communication. Of interest are the respective static values as well as their variations in time which might be due to environmental changes or due to rerouting. Basic aspects will be briefly addressed, a variety of standard and state-of-the-art characterization and monitoring techniques will be reviewed and recent experimental results will be presented.