Tuning with finesse [Broadband comb sources tuned via intracavity Fabry-Perot etalon]

Researchers at the Purdue University Ultrafast Optics and Optical Fiber Communications Laboratory in the US have reported tuning of the frequency envelope of a broadband comb source at 1.5-μm, generated from a semiconductor-based mode-locked ring laser with an intracavity high finesse Fabry-Perot etalon. Broadband, stable spectral comb sources find use in a number of applications, such as multiwavelength light sources, multi-channel dense WDM transmission, microwave photonic filters or signal processors and high speed optical communications. Wavelength tuning of such sources will lend flexibility in the device´s operation and may reduce the cost of system implementation by allowing the use of cheap passive and fixed counterpart components.