1,158 research outputs found
Unifying Brillouin scattering and cavity optomechanics
So far, Brillouin scattering and cavity optomechanics were mostly
disconnected branches of research -- although both deal with photon-phonon
coupling. This begs for the development of a broader theory that contains both
fields. Here, we derive the dynamics of optomechanical cavities from that of
Brillouin-active waveguides. This explicit transition elucidates the link
between phenomena such as Brillouin amplification and electromagnetically
induced transparency. It proves that effects familiar from cavity optomechanics
all have traveling-wave partners, but not vice versa. We reveal a close
connection between two parameters of central importance in these fields: the
Brillouin gain coefficient and the zero-point optomechanical coupling rate.
This enables comparisons between systems as diverse as ultracold atom clouds,
plasmonic Raman cavities and nanoscale silicon waveguides. In addition,
back-of-the-envelope calculations show that unobserved effects, such as
photon-assisted amplification of traveling phonons, are now accessible in
existing systems. Finally, we formulate both circuit- and cavity-oriented
optomechanics in terms of vacuum coupling rates, cooperativities and gain
coefficients, thus reflecting the similarities in the underlying physics.Comment: published manuscript, minor change
Design of weak 1-D bragg grating filters in SOI waveguides using volume holography techniques
To answer the growing need for more versatile integrated spectral filters, we show that weak one-dimensional gratings can be designed towards any desired target spectrum. We follow a very straightforward design procedure to demonstrate the performance of these devices. Measurements and simulations show a very good correspondence with the target spectra. By analyzing the results, we also found that the design procedure can be refined by using simulated reflections, instead of relying on the calculated Fresnel reflections
Focused-ion-beam fabricated vertical fiber couplers on silicon-on-insulator waveguides
We fabricated grating couplers in silicon-on-insulator waveguides with focused-ion-beam. First devices were very lossy, but by using selective etchant and a hard mask we obtained efficiencies comparable to traditional fabrication techniques
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