title: Tunable Q-factor silicon microring resonators for ultra-low power parametric processes.
abstract: A compact silicon ring resonator is demonstrated that allows simple electrical tuning of the ring coupling coefficient and Q-factor and therefore the resonant enhancement of on-chip nonlinear optical processes. Fabrication-induced variation in designed coupling fraction, crucial in the resonator performance, can be overcome using this post-fabrication trimming technique. Tuning of the microring resonator across the critical coupling point is demonstrated, exhibiting a Q-factor tunable between 9000 and 96,000. Consequently, resonantly enhanced four-wave mixing shows tunable efficiency between -40 and -16.3  dB at an ultra-low on-chip pump power of 0.7 mW.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Strain
authors.forename: Cosimo
authors.initials: C
authors.lastname: Lacava
authors.forename: Laura
authors.initials: L
authors.lastname: Meriggi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cristiani
authors.forename: Marc
authors.initials: M
authors.lastname: Sorel