title: Generation of a flexible optical comb in a periodically poled lithium niobate waveguide.
abstract: We propose and demonstrate a technique for the generation of an optical comb with tunable line spacing in a periodically poled lithium niobate (PPLN) waveguide. The technique is implemented with four input continuous waves (CWs), which generate a 19-line comb tuned to the spacing of 25 and 20 GHz. We show that each additional CW switched on out of the quasi phase-matching band at the PPLN waveguide input generates the growth of six new lines. The performance of the comb is tested modulating the lines with a 40 Gb/s differential quadrature phase shift keying data, demonstrating error-free operation. Nonuniform spacing of the input seed CWs improves the efficiency of the line generation process.
authors.forename: Mirco
authors.initials: M
authors.lastname: Scaffardi
authors.forename: Sergio
authors.initials: S
authors.lastname: Pinna
authors.forename: Emma
authors.initials: E
authors.lastname: Lazzeri
authors.forename: Antonella
authors.initials: A
authors.lastname: Bogoni