Design of tapering one-dimensional photonic crystal ultrahigh-Q microcavities

✍ Scribed by Qin Chen; Duncan W.E. Allsopp

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 501 KB
• Volume: 7
• Category: Article
• ISSN: 1569-4410
• DOI: 10.1016/j.photonics.2008.11.002

✦ Synopsis

One-dimensional (1D) photonic crystal (PC) microcavities can be readily embedded into silicon-on-insulator waveguides for photonic integration. Such structures are investigated by 2D Finite-Difference Time-Domain method to identify designs with high transmission which is essential for device integration. On-resonance transmission is found to decrease with the increasing mirror pairs, however, the quality factor (Q) increases to a saturated value. The addition to the Bragg mirrors of tapered periods optimized to produce a cavity mode with a near Gaussian shaped envelope results in a major reduction in vertical loss. Saturated Q up to 2.4 Â 10 6 is feasible if the internal tapers are properly designed. The effect of increasing transmission is also demonstrated in a structure with the external tapers.