title: Travelling-wave resonant four-wave mixing breaks the limits of cavity-enhanced all-optical wavelength conversion.
abstract: Wave mixing inside optical resonators, while experiencing a large enhancement of the nonlinear interaction efficiency, suffers from strong bandwidth constraints, preventing its practical exploitation for processing broad-band signals. Here we show that such limits are overcome by the new concept of travelling-wave resonant four-wave mixing (FWM). This approach combines the efficiency enhancement provided by resonant propagation with a wide-band conversion process. Compared with conventional FWM in bare waveguides, it exhibits higher robustness against chromatic dispersion and propagation loss, while preserving transparency to modulation formats. Travelling-wave resonant FWM has been demonstrated in silicon-coupled ring resonators and was exploited to realize a 630-μm-long wavelength converter operating over a wavelength range wider than 60 nm and with 28-dB gain with respect to a bare waveguide of the same physical length. Full compatibility of the travelling-wave resonant FWM with optical signal processing applications has been demonstrated through signal retiming and reshaping at 10 Gb s(-1).
authors.affiliation: Dipartimento di Elettronica e Informazione, Politecnico di Milano, 20133 Milano, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Morichetti
authors.forename: Antonio
authors.initials: A
authors.lastname: Canciamilla
authors.forename: Carlo
authors.initials: C
authors.lastname: Ferrari
authors.forename: Antonio
authors.initials: A
authors.lastname: Samarelli
authors.forename: Marc
authors.initials: M
authors.lastname: Sorel
authors.forename: Andrea
authors.initials: A
authors.lastname: Melloni