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Abstract
The ability to manipulate photons is of critical importance for both fundamental quantum optics studies and practical quantum communication applications. While integrated photonic circuits provide the unprecedented power to realize complex photon control with minimized structures, most materials used in integrated photonic circuits lack the preferred second-order optical nonlinearity, which limits photon control functionalities. On the other hand, the wurtzite crystal structure gives rise to the strong second-order optical nonlinearity and piezoelectric effect in aluminum nitride. Together with its low optical and mechanical losses, integrated aluminum nitride photonics can provide new aspects and enable novel methods for quantum photon control; pushing forward the frontier of quantum technology.
In this thesis, we present the theoretical and experimental study of quantum photon control based on integrated aluminum nitride photonics. First, we propose a cascaded optical transparency scheme for prolonged optical delay based on piezo-optomechanical systems, where both parametric phonon-phonon and optomechanical couplings are utilized. This scheme is experimentally demonstrated with an aluminum nitride suspended wheel structure. In addition to the optomechanical coupling, the parametric phonon-phonon coupling is observed with strong piezoelectric drive. Simultaneous improvement of optical transmission and delay are realized. Next, we study the adiabatic frequency shifting of single photons based on piezo-optomechanical systems. We demonstrate the first integrated optomechanical single-photon frequency shifter with near-unity efficiency. A frequency shift up to 150 GHz at telecom wavelength is realized without measurable added noise and the preservation of quantum coherence is verified through quantum interference between twin photons of different colors. Then we explore the coherent microwave-to-optical photon conversion based on the electro-optic effect. Superconducting microwave resonators based on NbTiN are integrated with aluminum nitride optical cavities. Both high quality microwave resonators and optical cavities are achieved simultaneously. Different phase matching conditions for coherent microwave-to-optical photon conversion are discussed. We show that unity internal conversion efficiency can be achieved under cryogenic environment.
Our study proves that integrated aluminum nitride photonics shows promise for quantum photon control. Based on piezo-optomechanical systems, the further development of ultra-deep optical modulation will be critical for many applications, ranging from optical comb generation, optical pulse generation, and time lens. etc. Based on cavity electro-optic systems, realizing the non-classical state conversion between microwave and optical domains will be a significant step toward the hybrid quantum network.