The authors report on the development and phase locking of a frequency agile laser. The use of a simple unbalanced Mach-Zehnder interferometer together with a wideband phase-locked loop permits to control very fast frequency chirps ͑up to 3 GHz in 5 s͒ with an excellent precision ͑frequency error less than 100 kHz͒. The servoloop could be applied to many tunable lasers.

No abstract

The performance and accuracy of a number of propagative algorithms are compared for the simulation of tapered high contrast step index slab waveguides. The considered methods include paraxial as well as nonparaxial formulations of optical field propagation. In particular attention is paid to the validity of the paraxial approximation. To test the internal consistency of the various methods the property of reciprocity is verified and it is shown that for the paraxial algorithms the reciprocity can only be fulfilled if the paraxial approximation of the power flux expression using the Poynting vector is considered. Finally, modeling results are compared with measured fiber coupling losses for an experimentally realized taper structure.

No abstract

No abstract