title: Athermal operation of silicon waveguides: spectral, second order and footprint dependencies.
abstract: We report the design criteria and performance of Si ring resonators for passive athermal applications in wavelength division multiplexing (WDM). The waveguide design rules address i) positive-negative thermo-optic (TO) composite structures, ii) resonant wavelength dependent geometry to achieve constant confinement factor (Gamma), and iii) observation of small residual second order effects. We develop exact design requirements for a temperature dependent resonant wavelength shift (TDWS) of 0 pm/K and present prototype TDWS performance of 0.5 pm/K. We evaluate the materials selection tradeoffs between high-index contrast (HIC) and low-index contrast (LIC) systems and show, remarkably, that FSR and footprint become comparable under the constraint of athermal design.
authors: Microphotonics Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. vivekr@mit.edu
authors: Vivek
authors: V
authors: Raghunathan
authors: Winnie N
authors: WN
authors: Ye
authors: Juejun
authors: J
authors: Hu
authors: Tomoyuki
authors: T
authors: Izuhara
authors: Jurgen
authors: J
authors: Michel
authors: Lionel
authors: L
authors: Kimerling
mesh_terms: D004581:Electronics / Q000295:instrumentation / Q000379:methods; D006358:Hot Temperature; D008962:Models, Theoretical; D055095:Optics and Photonics / Q000295:instrumentation* / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012031:Refractometry / Q000295:instrumentation / Q000379:methods; D012825:Silicon / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D011108:Polymers; D017655:Silicon Compounds; C032734:silicon nitride; D012825:Silicon