Optomechanics Research Papers - Academia.edu (original) (raw)

In the field of optomechanics, radiation forces have provided a particularly high level of control over the frequency and dissipation of mechanical elements. Here we propose a class of optomechanical systems in which light exerts a... more

In the field of optomechanics, radiation forces have provided a particularly high level of control over the frequency and dissipation of mechanical elements. Here we propose a class of optomechanical systems in which light exerts a similarly profound influence over two other fundamental parameters: geometry and mass. By applying an optical trap to one lattice site of an extended phononic crystal, we show it is possible to create a tunable, localized mechanical mode. Owing to light's simultaneous and constructive coupling with the structure's continuum of modes, we estimate that a trap power at the level of a single intracavity photon should be capable of producing a significant effect within a realistic, chip-scale device.

We study the entanglement dynamics of two coupled mechanical oscillators, within a modulated optomechanical system. We find that, depending on the strength of the mechanical coupling, one could observe either a stationary or a dynamical... more

We study the entanglement dynamics of two coupled mechanical oscillators, within a modulated optomechanical system. We find that, depending on the strength of the mechanical coupling, one could observe either a stationary or a dynamical behavior of the mechanical entanglement, which is extremely robust against the oscillator temperature. Moreover, we have shown that this entanglement dynamics is strongly related to the stability of the normal modes. Taking mechanical damping effects into account, an analytical expression corresponding to the critical mechanical coupling strength, where the transition from stationary to dynamical entanglement occurs is also reported. The proposed scheme is analysed with experimentally realistic parameters, making it a promising mean to realize macroscopic quantum entanglement within current state-of-the-art experimental setups.

Droplets, particularly water droplets, are abundant in both natural and artificial systems. Their capillary oscillations are governed by surface tension and are therefore distinguished from acoustic oscillations. These capillary... more

Droplets, particularly water droplets, are abundant in both natural and artificial systems. Their capillary oscillations are governed by surface tension and are therefore distinguished from acoustic oscillations. These capillary oscillations play a major role in droplet coalescence, for example, and are also an important phenomenon in interface theories. Here, we experimentally and theoretically analyze the capillary oscillation within an optical cavity with walls of water. Our droplet benefits from an optical finesse of 520 that, accordingly, boosts its sensitivity in recording Brownian capillaries with amplitudes of 1 0.025 Å and kilohertz rates in agreement with natural-frequency calculations. Our hybrid device allows resonantly enhanced interactions between electromagnetic and capillary waves that could potentially lead to optical excitation or the cooling of droplet capillary oscillations.

The National Ignition Facility and the Omega Laser Facility both have a need for measuring prompt gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic using off-axis-parabolic mirrors has been built.... more

The National Ignition Facility and the Omega Laser Facility both have a need for measuring prompt gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic using off-axis-parabolic mirrors has been built. Some new techniques were used in the design, construction, and tolerancing of this gamma ray diagnostic. Because of the wavelength requirement (250 to 700 nm), the optical element surface finishes were a key design consideration. The optical enclosure had to satisfy pressure safety concerns and shielding against electromagnetic interference induced by gammas and neutrons. Structural finite element analysis was needed to meet rigorous optical and safety requirements. The optomechanical design is presented. Alignment issues are also discussed.

"En este trabajo se emplearon pulsos láser ultracortos (110 fs, 1 kHz; hasta1.1 mJ/pulso) para el micro-perforado de acero. El procesado con estos pulsos permitió obtener agujeros circulares, con medidas precisas y sin alteración mecánica... more

"En este trabajo se emplearon pulsos láser ultracortos (110 fs, 1 kHz; hasta1.1 mJ/pulso) para el micro-perforado de acero. El procesado con estos pulsos permitió obtener agujeros circulares, con medidas precisas y sin alteración mecánica ni química apreciable de las zonas adyacentes. Los agujeros se realizaron utilizando el sistema de trepanado óptico (Helical Drilling Optics,HDO) de la empresa TGSW-Stuttgart, el cual permitió generar estructuras no sólo de gran profundidad sino además de diámetro variable, gracias a que se pudo variar hasta tres parámetros de proceso simultáneamente (velocidad de rotación del haz, inclinación y descentrado del haz respecto del eje óptico)mientras se ejecutaba el procesado. En el presente trabajo se estudió principalmente la influencia de la longitud de onda del láser, en la geometría de las micro-perforaciones. Para ello se realizó la micro-perforación con pulsos láser con la longitud de onda fundamental (λ= 790nm) y la del segundo armónico(λ= 395nm), se utilizó un conjunto específico de elementos ópticos para la HDO en cada caso y se compararon los resultados obtenidos lo cual arrojó que no hay ventajas notables al usar el segundo armónico. Se mencionan deficiencias en el dispositivo experimental que impidieron evaluar la influencia de la longitud de onda con total precisión"