Non-volatile resonance modes of a photonic cavity in diamond produced by fine-tuning

Methods of fine-tuning the properties of 1D triangular nanobeam diamond based photonic devices, with the aim of enhancing the photon collection efficiency at predetermined wavelengths at ambient temperature, are described. Delicate control of the physical dimensions of the device, which is required to obtain these advantages, is achieved by the deposition of HfO2 monolayers (thickening) and by H2 plasma etching (thinning). These shift the optical properties of the thus-treated photonic crystal to the red and to the blue, respectively. The methods described here demonstrate a practical and straight-forward way to fine-tune the diamond photonic nanocavity into resonance with the zero-phonon line of the Nitrogen-Vacancy (NV-) centers at room temperature with the availability to be kept storable. This approach paves the way to obtain a non-volatile nanobeam structure available at a desired predetermined resonance mode for a subsequent usage of the NV- emission in ambient conditions. It may find valuable applications in diamond-based quantum computing and communications.