Photonics Research, Volume. 8, Issue 8, 1333(2020)
Unidirectional reflection from an integrated “taiji” microresonator
Fig. 1. Sketch of the taiji microresonator:
Fig. 2. Panels (a) and (b): numerical results for the field intensity in the taiji microresonator with light incident from the left and right, respectively. The geometrical dimensions are in μm. The frequency is resonant with the ring and the bus waveguide is critically coupled. The color plot shows the electric field amplitude in V/m. It is noteworthy that only light incident from the right excites the S waveguide. This highlights the non-symmetrical behavior of light reflection. Panels (c) and (d): transmitted (blue dots) and reflected intensity as a function of the incident wavelength for light incident from the left (black dots) and from the right (green dots). The red lines display the fitting results employing the analytical model.
Fig. 3. Panels (a) and (b) show the optical micrograph and the SEM image of the top and the cross-section view of a taiji microresonator, respectively. Panel (c): sketch of the experimental setup.
Fig. 4. Experimental spectra of the (a) transmitted and (b), (c) reflected intensities as a function of the incident wavelength. The blue lines show the experimental measurements while the red lines display the fitting results employing the analytical model. The bottom panels show the zoom of the transmitted (Zoom 1) and reflected (Zoom 2, 3) intensities for the resonance highlighted by the vertical dashed lines.
Fig. 5. Intensity as a function of the wavelength computed with the Eqs. (
Fig. 6. Map of the fields within the device, used to calculate the scattering matrix elements when light enters from the left. Labels
Fig. 7. Map of the fields within the device, used to calculate the scattering matrix elements when light enters from the right. Again
Fig. 8. Results of the simulation of the ring-bus waveguide coupling region of the taiji. Plotted curves represent the power transmission to either the bus waveguide or the ring, as a function of their mutual separation. The inset shows the distribution of electric field amplitude in the system in V/m, for a chosen distance of 335 nm. Geometrical dimensions are in μm.
Fig. 9. Results of the simulation of the ring-S-shaped waveguide coupling region of the taiji. Plotted curves represent the power transmission to either the ring or the S-shaped branch, as a function of their mutual separation. The inset shows the distribution of electric field amplitude in the system in V/m, for a chosen distance of 289 nm. Geometrical dimensions are in μm.
Get Citation
Copy Citation Text
A. Calabrese, F. Ramiro-Manzano, H. M. Price, S. Biasi, M. Bernard, M. Ghulinyan, I. Carusotto, L. Pavesi, "Unidirectional reflection from an integrated “taiji” microresonator," Photonics Res. 8, 1333 (2020)
Category: Optical Devices
Received: Mar. 18, 2020
Accepted: May. 26, 2020
Published Online: Jul. 21, 2020
The Author Email: S. Biasi (stefano.biasi@unitn.it)