Professional Education


  • Bachelor of Science, Universiteit Gent (2009)
  • Master of Science, Universiteit Gent (2011)
  • Doctor of Philosophy, Universiteit Gent (2016)

Stanford Advisors


All Publications


  • A silicon-organic hybrid platform for quantum microwave-to-optical transduction QUANTUM SCIENCE AND TECHNOLOGY Witmer, J. D., McKenna, T. P., Arrangoiz-Arriola, P., Van Laer, R., Alex Wollack, E., Lin, F., Jen, A., Luo, J., Safavi-Naeini, A. H. 2020; 5 (3)
  • Time-of-flight imaging based on resonant photoelastic modulation (vol 58, pg 2235, 2019) APPLIED OPTICS Atalar, O., Van Laer, R., Sarabalis, C. J., Safavi-Naeini, A. H., Arbabian, A. 2020; 59 (5): 1430

    Abstract

    This publisher's note corrects the Funding section in Appl. Opt.58, 2235 (2019)APOPAI0003-693510.1364/AO.58.002235.

    View details for DOI 10.1364/AO.389202

    View details for Web of Science ID 000526522300059

    View details for PubMedID 32225397

  • Efficient bidirectional piezo-optomechanical transduction between microwave and optical frequency. Nature communications Jiang, W., Sarabalis, C. J., Dahmani, Y. D., Patel, R. N., Mayor, F. M., McKenna, T. P., Van Laer, R., Safavi-Naeini, A. H. 2020; 11 (1): 1166

    Abstract

    Efficient interconversion of both classical and quantum information between microwave and optical frequency is an important engineering challenge. The optomechanical approach with gigahertz-frequency mechanical devices has the potential to be extremely efficient due to the large optomechanical response of common materials, and the ability to localize mechanical energy into a micron-scale volume. However, existing demonstrations suffer from some combination of low optical quality factor, low electrical-to-mechanical transduction efficiency, and low optomechanical interaction rate. Here we demonstrate an on-chip piezo-optomechanical transducer that systematically addresses all these challenges to achieve nearly three orders of magnitude improvement in conversion efficiency over previous work. Our modulator demonstrates acousto-optic modulation with [Formula: see text] = 0.02 V. We show bidirectional conversion efficiency of [Formula: see text] with 3.3 μW  red-detuned optical pump, and [Formula: see text] with 323 μW blue-detuned pump. Further study of quantum transduction at millikelvin temperatures is required to understand how the efficiency and added noise are affected by reduced mechanical dissipation, thermal conductivity, and thermal capacity.

    View details for DOI 10.1038/s41467-020-14863-3

    View details for PubMedID 32127538

  • Cryogenic packaging of an optomechanical crystal OPTICS EXPRESS McKenna, T. P., Patel, R. N., Witmer, J. D., Van Laer, R., Valery, J. A., Safavi-Naeini, A. H. 2019; 27 (20): 28782–91
  • Lithium niobate piezo-optomechanical crystals OPTICA Jiang, W., Patel, R. N., Mayor, F. M., Mckenna, T. P., Arrangoiz-Arriola, P., Sarabalis, C. J., Witmer, J. D., Van Laer, R., Safavi-Naeini, A. H. 2019; 6 (7): 845–53
  • Resolving the energy levels of a nanomechanical oscillator. Nature Arrangoiz-Arriola, P., Wollack, E. A., Wang, Z., Pechal, M., Jiang, W., McKenna, T. P., Witmer, J. D., Van Laer, R., Safavi-Naeini, A. H. 2019; 571 (7766): 537–40

    Abstract

    The quantum nature of an oscillating mechanical object is anything but apparent. The coherent states that describe the classical motion of a mechanical oscillator do not have a well defined energy, but are quantum superpositions of equally spaced energy eigenstates. Revealing this quantized structure is only possible with an apparatus that measures energy with a precision greater than the energy of a single phonon. One way to achieve this sensitivity is by engineering a strong but nonresonant interaction between the oscillator and an atom. In a system with sufficient quantum coherence, this interaction allows one to distinguish different energy eigenstates using resolvable differences in the atom's transition frequency. For photons, such dispersive measurements have been performed in cavity1,2 and circuit quantum electrodynamics3. Here we report an experiment in which an artificial atom senses the motional energy of a driven nanomechanical oscillator with sufficient sensitivity to resolve the quantization of its energy. To realize this, we build a hybrid platform that integrates nanomechanical piezoelectric resonators with a microwave superconducting qubit on the same chip. We excite phonons with resonant pulses and probe the resulting excitation spectrum of the qubit to observe phonon-number-dependent frequency shifts that are about five times larger than the qubit linewidth. Our result demonstrates a fully integrated platform for quantum acoustics that combines large couplings, considerable coherence times and excellent control over the mechanical mode structure. With modest experimental improvements, we expect that our approach will enable quantum nondemolition measurements of phonons4 and will lead to quantum sensors and information-processing approaches5 that use chip-scale nanomechanical devices.

    View details for DOI 10.1038/s41586-019-1386-x

    View details for PubMedID 31341303

  • Controlling phonons and photons at the wavelength scale: integrated photonics meets integrated phononics (vol 6, pg 213, 2019) OPTICA Safavi-Naeini, A. H., Van Thourhout, D., Baets, R., Van Laer, R. 2019; 6 (4): 410
  • Time-of-flight imaging based on resonant photoelastic modulation APPLIED OPTICS Atalar, O., Van Laer, R., Sarabalis, C. J., Safavi-Naeini, A. H., Arbabian, A. 2019; 58 (9): 2235–47
  • Controlling phonons and photons at the wavelength scale: integrated photonics meets integrated phononics OPTICA Safavi-Naeini, A. H., Van Thourhout, D., Baets, R., Van Laer, R. 2019; 6 (2): 213–32
  • Microwave Quantum Acoustic Processor Arrangoiz-Arriola, P., Wollack, E., Pechal, M., Jiang, W., Wang, Z., McKenna, T. P., Witmer, J., Van Laer, R., Cleland, A., Lee, N., Sarabalis, C. J., Stas, P., Safavi-Naeini, A. H., IEEE IEEE. 2019: 255–58
  • Electro-Optics with Gigahertz Phonons in Silicon Photonics Van Laer, R., Patel, R. N., Witmer, J. D., McKenna, T. P., Safavi-Naeini, A. H., IEEE IEEE. 2019
  • High-quality Lithium Niobate Optomechanical Crystal Jiang, W., Patel, R. N., Mayor, F. M., McKenna, T. P., Arrangoiz-Arriola, P., Sarabalis, C. J., Van Laer, R., Safavi-Naeini, A. H., IEEE IEEE. 2019
  • Optomechanical antennas for on-chip beam-steering OPTICS EXPRESS Sarabalis, C. J., Van Laer, R., Safavi-Naeini, A. H. 2018; 26 (17): 22075–99

    Abstract

    Rapid and low-power control over the direction of a radiating light field is a major challenge in photonics and a key enabling technology for emerging sensors and free-space communication links. Current approaches based on bulky motorized components are limited by their high cost and power consumption, while on-chip optical phased arrays face challenges in scaling and programmability. Here, we propose a solid-state approach to beam-steering using optomechanical antennas. We combine recent progress in simultaneous control of optical and mechanical waves with remarkable advances in on-chip optical phased arrays to enable low-power and full two-dimensional beam-steering of monochromatic light. We present a design of a silicon photonic system made of photonic-phononic waveguides that achieves 44° field of view with 880 resolvable spots by sweeping the mechanical wavelength with about a milliwatt of mechanical power. Using mechanical waves as nonreciprocal, active gratings allows us to quickly reconfigure the beam direction, beam shape, and the number of beams. It also enables us to distinguish between light that we send and receive.

    View details for DOI 10.1364/OE.26.022075

    View details for Web of Science ID 000442136200061

    View details for PubMedID 30130907

  • Thermal Brillouin noise observed in silicon optomechanical waveguide JOURNAL OF OPTICS Van Laer, R., Sarabalis, C. J., Baets, R., Van Thourhout, D., Safavi-Naeini, A. H. 2017; 19 (4)
  • Enabling Strong Coupling in Nanoscale Silicon Optomechanical Waveguides Van Laer, R., Safavi-Naeini, A., IEEE IEEE. 2017