Ultra-compact and wide-spectrum-range thermo-optic switch based on silicon coupled photonic crystal microcavities
Abstract
We design, fabricate, and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78 μm-long coupled L0-type photonic crystal microcavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystal microcavity. Coupling between identical microcavities gives rise to bonding and anti-bonding states of the coupled photonic molecules. The coupled photonic crystal microcavities are numerically simulated and experimentally verified with a 6 nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20 dB, an on-off switching power of 18.2 mW, a thermo-optic tuning efficiency of 0.63 nm/mW, a rise time of 14.8 μs, and a fall time of 18.5 μs. The measured on-chip loss on the transmission band is as low as 1 dB.
- Publication:
-
Applied Physics Letters
- Pub Date:
- November 2015
- DOI:
- 10.1063/1.4936611
- arXiv:
- arXiv:1601.04763
- Bibcode:
- 2015ApPhL.107v1104Z
- Keywords:
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- Physics - Optics
- E-Print:
- Appl. Phys. Lett. 107, 221104 (2015)