Diamond Photonics and Quantum Optics:
Diamond has recently emerged as a remarkable material system for photonics and quantum optics. Emerging applications include: (1) nanophotonic devices with integrated color centers for room temperature quantum cryptography, quantum information processing, and cavity QED; (2) biocompatible devices for photonics-based chemical sensing schemes; and (3) high-frequency mechanical oscillators for optomechanical systems. Towards these ends, the Loncar Lab is investigating a variety of device architectures based on single crystal diamond samples, semiconductor microcavities (e.g. SiNx, TiO2) with embedded diamond nanoparticles, and hybrid metal-diamond plasmonic devices. Our lab is fully equipped with the experimental tools needed to study these devices: home-built confocal microscopes, liquid Helium cryostat, high-resolution spectrometer, single-photon detectors, Ti:Sapphire laser with pulse picker (ps or fs pulse configurations), a tunable red laser, coherent white light source, and a streak camera.
These projects benefit greatly from collaborations with Phil Hemmer (Texas A&M), Fedor Jelezko (Stuttgart), and the Lukin and Yacoby labs (Harvard). Funding for this project is generously provided by Harvard’s Nanoscale Science and Engineering Center (NSEC), a NSF NIRT grant, and the DARPA QuEST program.
Figure 1. (Left) The Nitrogen-vacancy (NV) color center is a room-temperature source of single photons and its spin state can be optically read-out. This is an excellent candidate for integrating spin and photonic qubits on-chip. We are currently focusing on the design, fabrication, and characterization of nanophotonic devices with embedded Nitrogen-vacancy (NV) centers. (Right) Cartoon of diamond nanowire waveguides containing individual NV centers, which can be used to realize enhanced collection of single photons for sensitive (single-shot) read-out and magnetometry, for example.
Figure 2. (Left) SEM micrograph of diamond nanowires from a single crystal sample. Nanowire waveguides were fabricated with e-beam lithography to define circular masks on the crystal surface and ICP RIE etching to transfer the pattern into the crystal. Devices with lengths up to 4um have been fabricated using our recipe, and these are readily transferred to other substrates for additional processing. (Right) Confocal microscope image of a typical device array, including a nanowire containing a well-coupled NV center.
Figure 3. (Left) Photon antibunching from a diamond nanowire demonstrates non-classical light emission from a single NV center, (Right) and its photoluminescence spectrum shows a room-temperature zero-phonon line at 637nm and phonon sideband from ~640-780nm.
References:
Figure 1. (Left) The Nitrogen-vacancy (NV) color center is a room-temperature source of single photons and its spin state can be optically read-out. This is an excellent candidate for integrating spin and photonic qubits on-chip. We are currently focusing on the design, fabrication, and characterization of nanophotonic devices with embedded Nitrogen-vacancy (NV) centers. (Right) Cartoon of diamond nanowire waveguides containing individual NV centers, which can be used to realize enhanced collection of single photons for sensitive (single-shot) read-out and magnetometry, for example.
Figure 2. (Left) SEM micrograph of diamond nanowires from a single crystal sample. Nanowire waveguides were fabricated with e-beam lithography to define circular masks on the crystal surface and ICP RIE etching to transfer the pattern into the crystal. Devices with lengths up to 4um have been fabricated using our recipe, and these are readily transferred to other substrates for additional processing. (Right) Confocal microscope image of a typical device array, including a nanowire containing a well-coupled NV center.
Figure 3. (Left) Photon antibunching from a diamond nanowire demonstrates non-classical light emission from a single NV center, (Right) and its photoluminescence spectrum shows a room-temperature zero-phonon line at 637nm and phonon sideband from ~640-780nm.
References:
- Y. Zhang and M. Loncar, “Sub-micron diameter micropillar cavities with high Quality factors and ultra-small mode volumes”, Optics Letters, Vol. 34, 902 (2009).
- M. W. McCutcheon and M. Loncar, “Design of an ultrahigh Quality factor silicon nitride photonic crystal nanocavity for coupling to diamond nanocrystals”, Optics Express, Vol. 15, 19136 (2008).
- B. H. Hausmann, M. Khan, T. Babinec, Y. Zhang, K. Martinick, M. W. McCutcheon, P. R. Hemmer, and M. Loncar, “Fabrication of diamond nanowires for QIP applications”, arXiv:0908.0352.
- T. Babinec, B. Hausmann, M. Khan, Y. Zhang, J. Maze, P. R. Hemmer, and M. Loncar, “A bright single photon source based on a diamond nanowire”, arXiv:0908.0233.