Experimental Realization of an On-Chip All-Optical Analogue to Electromagnetically Induced Transparency

We provide the first experimental observation of structure tuning of the electromagnetically induced transparencylike spectrum in integrated on-chip optical resonator systems. The system consists of coupled silicon ring resonators with $10\mu \mathrm{m}$ diameter on silicon, where the coherent interference between the two coupled resonators is tuned. We measured a transparency-resonance mode with a quality factor of 11 800.

Figure 1

Microscope picture of the fabricated microring-resonator system.

Figure 2

Experimental transmission spectra (black, solid line) and theoretical fits (red, dashed line) for the microring-resonator system of Fig. 1. Curves (a)–(e) correspond to five different devices with varying ring separations $s$. Successive curves have been offset by $-0.5$ units for clarity. (a) $s=15.69\mu \mathrm{m}$. (b) $s=15.71\mu \mathrm{m}$. (c) $s=15.73\mu \mathrm{m}$. (d) $s=15.75\mu \mathrm{m}$. (e) $s=15.77\mu \mathrm{m}$.

Figure 3

Optical mode at the EIT-like transparency-resonance imaged by collecting the top-scattered light at the transparency peak ${\lambda }_{\mathrm{tr}}$.