講演情報
[21a-A308-2]Measurement of band structure in the synthetic frequency dimensions
for a silicon-based coupled two ring resonators
〇Runming Zhang1, Liucun Li2, Mikiya Kamata2, Toshihiko Baba2, Tomoki Ozawa3, Yasutomo Ota4, Satoshi Iwamoto1 (1.Univ. of Tokyo, 2.Yokohama Nat'l Univ., 3.Tohoku Univ., 4.Keio Univ.)
キーワード：
photonic、synthetic dimension
In photonics, synthetic dimensions, in which one or more spatial dimensions are replaced with non-spatial degrees of freedom of light, are recently receiving attentions [1]. Topological chiral edge states in synthetic dimensions allow realization of an optical isolator without the use of magneto-optical materials [2,3]. Using a single silicon ring resonator, photonic dispersion in a synthetic dimension and its modification under synthetic gauge fields have been demonstrated [4]. To explore rich physics in the synthetic dimension and realize novel photonic devices, it is essential to extend the system from a single resonator to coupled resonators. In this study, as the first step, we fabricated a coupled two ring resonators by a silicon CMOS process and measured the band structures in a synthetic dimension.
Figure 1 (a) shows the schematic device configuration and a photograph of one of the fabricated devices. The devices are composed of two ring resonators coupled to each other via an MMI coupler, whose splitting ratio can be controlled by injecting a current into the coupler. The cavity length of each ring resonator is ~4.2 mm, corresponding to FSR of ~19GHz. Each ring resonator is equipped with an optical modulator. We generated a lattice in the synthetic frequency dimension by applying an RF signal at the frequency of 18.66 GHz to each modulator and measured the band structure by time-resolved transmission measurements either at Port 1 or Port 2. One of the measured band structures at Port 2 is shown in Fig. 1(b). The results show features similar to the theoretical band structure calculated based on the model in [5] when the phase difference of two RF signals is p ( Fig. 1(c)). The band structures measured at different conditions and the detailed analysis will be discussed in the presentation.
Figure 1 (a) shows the schematic device configuration and a photograph of one of the fabricated devices. The devices are composed of two ring resonators coupled to each other via an MMI coupler, whose splitting ratio can be controlled by injecting a current into the coupler. The cavity length of each ring resonator is ~4.2 mm, corresponding to FSR of ~19GHz. Each ring resonator is equipped with an optical modulator. We generated a lattice in the synthetic frequency dimension by applying an RF signal at the frequency of 18.66 GHz to each modulator and measured the band structure by time-resolved transmission measurements either at Port 1 or Port 2. One of the measured band structures at Port 2 is shown in Fig. 1(b). The results show features similar to the theoretical band structure calculated based on the model in [5] when the phase difference of two RF signals is p ( Fig. 1(c)). The band structures measured at different conditions and the detailed analysis will be discussed in the presentation.