title: Femtosecond laser writing of a flat-top interleaver via cascaded Mach-Zehnder interferometers.
abstract: A flat-top interleaver consisting of cascaded Mach-Zehnder interferometers (MZIs) was fabricated in bulk glass by femtosecond laser direct writing. Spectral contrast ratios of greater than 15 dB were demonstrated over a 30 nm bandwidth for 3 nm channel spacing. The observed spectral response agreed well with a standard transfer matrix model generated from responses of individual optical components, demonstrating the possibility for multi-component optical design as well as sufficient process accuracy and fabrication consistency for femtosecond laser writing of advanced optical circuits in three dimensions.
authors.affiliation: Department of Electrical and Computer Engineering and the Institute for Optical Sciences, University of Toronto, 10 King’s College Rd., Toronto, Ontario, M5S 3G4, Canada. jasonc.ng@mail.utoronto.ca
authors.forename: Jason C
authors.initials: JC
authors.lastname: Ng
authors.forename: Chengbo
authors.initials: C
authors.lastname: Li
authors.forename: Peter R
authors.initials: PR
authors.lastname: Herman
authors.forename: Li
authors.initials: L
authors.lastname: Qian