6 research outputs found
Multimode optomechanical weighing of a single nanoparticle
We demonstrate multimode optomechanical sensing of individual nanoparticles
with radius of a hundred of nanometers. A semiconductor optomechanical disk
resonator is optically driven and detected under ambient conditions, as
nebulized nanoparticles land on it. Multiple mechanical and optical resonant
signals of the disk are tracked simultaneously, providing access to several
physical informations about the landing analyte in real-time. Thanks to a fast
camera registering the time and position of landing, these signals can be
employed to weigh each nanoparticle with precision. Sources of error and
deviation are discussed and modeled, indicating a path to evaluate the
elasticity of the nanoparticles on top of their mere mass. The device is
optimized for future investigation of biological particles in the high
megadalton range, such as large viruses
Optomechanical measurement of single nanodroplet evaporation with millisecond time-resolution
Tracking the evolution of an individual nanodroplet of liquid in real-time
remains an outstanding challenge. Here a miniature optomechanical resonator
detects a single nanodroplet landing on a surface and measures its subsequent
evaporation down to a volume of twenty attoliters. The ultra-high mechanical
frequency and sensitivity of the device enable a time resolution below the
millisecond, sufficient to resolve the fast evaporation dynamics under ambient
conditions. Using the device dual optical and mechanical capability, we
determine the evaporation in the first ten milliseconds to occur at constant
contact radius with a dynamics ruled by the mere Kelvin effect, producing
evaporation despite a saturated surrounding gas. Over the following hundred of
milliseconds, the droplet further shrinks while being accompanied by the
spreading of an underlying puddle. In the final steady-state after evaporation,
an extended thin liquid film is stabilized on the surface. Our optomechanical
technique opens the unique possibility of monitoring all these stages in
real-time
Efficient optical coupling to gallium arsenide nano-waveguides and resonators with etched conical fibers
We explore new methods for coupling light to on-chip gallium arsenide
nanophotonic structures using etched conical optical fibers. With a
single-sided conical fiber taper, we demonstrate efficient coupling to an
on-chip photonic bus waveguide in a liquid environment. We then show that it is
possible to replace such on-chip bus waveguide by two joined conical fibers in
order to directly couple light into a target whispering gallery disk resonator.
This latter approach proves compliant with demanding environments, such as a
vibrating pulse tube cryostat operating at low temperature, and it is
demonstrated both in the telecom band and in the near infrared close to 900 nm
of wavelength. The versatility, stability, and high coupling efficiency of this
method are promising for quantum optics and sensing experiments in constrained
environments, where obtaining high signal-to-noise ratio remains a challenge
Multifrequency Nanomechanical Mass Spectrometer Prototype for Measuring Viral Particles Using Optomechanical Disk Resonators
Nanomechanical mass spectrometry allows characterization of analytes with broad mass range, from small proteins to bacterial cells, and with unprecedented mass sensitivity. In this work, we show a novel multifrequency nanomechanical mass spectrometer prototype designed for focusing, guiding and soft-landing of nanoparticles and viral particles on a nanomechanical resonator surface placed in vacuum. The system is compatible with optomechanical disk resonators, with an integrated optomechanical transduction method, and with the laser beam deflection technique for the measurement of the vibrations of microcantilever resonators. The prototype allows the in-vacuum alignment of resonators thanks to a dedicated visualization system. Finally, in this work, we have demonstrated the detection of gold nanoparticles, polystyrene nanoparticles and phage G viruses with optomechanical disks and microcantilever resonators.Peer reviewe