Marvyn’s dispersion engineering with alumina is on arXiv!

Check out this preprint (! Accompanying datasets and COMSOL simulation scripts are available on Zenodo (

Silica optical microspheres often exhibit ultra-high quality factors, yet, their group velocity dispersion, which is crucial for nonlinear optics applications, can only be coarsely tuned. We experimentally demonstrate that group-velocity dispersion of a silica microsphere can be engineered by coating it with conformal nanometric layers of alumina, yet preserving its ultra-high optical quality factors (\num{\sim e7}) at telecom wavelengths. Using the atomic layer deposition technique for the dielectric coating, which ensures nm-level thickness control, we not only achieve a fine dispersion tailoring but also maintain a low surface roughness and material absorption to ensure a low optical loss. Numerical simulations supporting our experimental results show that the alumina layer thickness is a promising technique for precise tuning of group-velocity dispersion. As an application we demonstrate the generation of Kerr optical frequency combs, showing that the alumina coatings can also sustain the high optical intensities necessary for nonlinear optical phenomena.

Natália’s GaAs bullseye structures pre-print on arXiv!

High-Frequency GaAs Optomechanical Bullseye Resonator

N. C. Carvalho, R. Benevides, M. Ménard, G. S. Wiederhecker, N. C. Frateschi, T. P. M. Alegre

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LPD CLEO 2020 talks

André’s preprint on Non-hermitian Optomechanics is online on arXiv!

Quasinormal-mode perturbation theory for dissipative and dispersive optomechanics

André G. Primo, Natália C. Carvalho, Cauê M. Kersul, Newton C. Frateschi, Gustavo S. Wiederhecker, Thiago P. Mayer Alegre

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Laís paper on Dispersion engineering with Wedge resonators is published in Optics Letters!

Dispersion tailoring in wedge microcavities for Kerr comb generation

Our plasmonic colors just came out in ACS Applied Nano Materials

Congratulations to Emerson and all the team! This is our first paper on plasmonics structures!

Check it out at

New paper on GaAs optomechanics just published in Optical Materials Express. Congratulations Rodrigo!

A method to fabricate GaAs microcavities using only a soft mask with an electrolithographic pattern in an inductively coupled plasma etching is presented. A careful characterization of the fabrication process pinpointing the main routes for a smooth device sidewall is discussed. Using the final recipe, optomechanical microdisk resonators are fabricated. The results show very high optical quality factors of Qopt > 2 × 105, among the largest already reported for dry-etching devices. The final devices are also shown to present high mechanical quality factors and an optomechanical vacuum coupling constant of g0 = 2π × 13.6 kHz enabling self-sustainable mechanical oscillations for an optical input power above 1 mW.

André receives SBFOTON award for his excellent talk

Congratulations to PhD candidate André Primo! Got awarded  for his outstanding talk on  bolometric optical forces at  the SBFoton conference 2019! 

Several postdoc positions available at our group!

Please check our post-doc  Opportunities. Application deadline coming up soon in late October and early November!

Brillouin optomechanics tutorial is out!

Brillouin optomechanics in nanophotonic structure

APL Photonics 4, 071101 (2019);
This tutorial guides and motivates scientists delving into the core of light-sound interaction. Through tangible examples, we lay out key concepts underneath accurate prediction of Brillouin gain in optomechanical structures. We have also published a data set at Zenodo repository with all the simulation files and data to generate every and each paper’s figures. 
Data repository for the tutorial paper ‘Brillouin optomechanics in nanophotonic structures,’