title: Precision resonance tuning and design of SiN photonic crystal reflectors.
abstract: Photonic crystal reflector (PCR) membranes exhibit a resonantly enhanced normal-incidence reflectivity. Many applications require this resonance to occur at a specific wavelength, however, imposing geometrical tolerances that are not reliably achieved with standard nanolithography. Here we finely tune the resonant wavelength of a freestanding Si3N4PCR membrane with iterative hydrofluoric acid etches, achieving a 57 nm thin crystal with a resonant wavelength 0.15 nm (0.04 linewidths) away from our target (1550 nm). This thin crystal exhibits a broader, shallower transmission dip than its simulated response to plane waves, and we identify two causes related to beam collimation. Finally, we present a series of simulations and general design considerations for realizing robust, high-reflectivity resonances.
authors.forename: Simon
authors.initials: S
authors.lastname: Bernard
authors.forename: Christoph
authors.initials: C
authors.lastname: Reinhardt
authors.forename: Vincent
authors.initials: V
authors.lastname: Dumont
authors.forename: Yves-Alain
authors.initials: YA
authors.lastname: Peter
authors.forename: Jack C
authors.initials: JC
authors.lastname: Sankey