Mechanically-tunable optical filter with microring resonators
Tunable optical filters are key components in dynamically reconfigurable wavelength-division-multiplexing (WDM) network.
For the photonic integrated circuit (PIC) platform, microring resonators are well-suited resonators, to be used for wavelength selection.
Conventional wavelength-tuning methods (i.e. refractive index tuning)
- Thermo-optic (Joule heaters)
- Carrier injection (free carrier plasma)
- Both of the methods above require high standing power consumption.
Proposed mechanical tuning methods (Figure 1)
- No or minimal standing power consumption
- Fast speed (microseconds)
- Simple structure
- Incomplex fabrication
Fig. 1. Schematic diagrams of the proposed tunable optical filters (a) with an out-of-plane actuator, and (b) with an in-plane actuator.
Calculated filter performance with 2-D finite-difference time-domain (FDTD) methods.
Fig. 2. Snapshots from the FDTD simulation.
Fig. 3. Output power at the DROP port for various gaps between the index modulator and the microring.