fabrication-and-testing-of-microfluidic-optomechanical-oscillators

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

University of Illinois at Urbana-Champaign

Primary orbital and primary breast lymphomas comprise very small subgroups of extranodal lymphomas. Clinical presentation at both these sites together is extremely rare. We describe a case of bilateral orbital and bilateral breast mucosa-associated lymphoid tissue (MALT) lymphomas with bilateral pre-auricular lymph nodal metastasis. The case history, staging and management for this unusual entity are discussed.

Synchronous mucosa-associated lymphoid tissue (MALT) lymphomas involving bilateral orbits and breasts: a rare clinical entity.

Radiotherapy alone for nasal natural-killer/T-cell lymphoma.

This single institutional study evaluated the prognostic factors and treatment outcome of 113 Indian patients with primary nasopharyngeal non-Hodgkin's lymphoma. At presentation, 28% had stage I and 62% had stage II disease. Treatment comprised of a combination of chemotherapy (CTh) and radiotherapy (RT) in the majority of the patients (76%). After a median follow-up of 56 months, the 5-year disease-free survival (DFS) and overall survival (OS) for the whole group were 55.8% and 57.9%, respectively. Multivariate analysis showed that; age > 30 years [hazard ratio (HR) = 6.59, 95% confidence interval (CI) = 2.59 - 16.7, P < 0.0001], WHO performance score > or = 2 (HR = 2.34, 95% CI = 1.01 - 5.46, P = 0.050), T-cell lymphomas (HR = 2.81, 95% CI = 1.14 - 6.96, P < 0.001) and the presence of B symptoms (HR = 3.65, 95% CI = 1.77 - 7.53, P = 0.025), had a negative influence on survival. Patients treated with a combination of CTh and RT had a significantly better outcome than those treated with CTh alone (OS: 69%vs. 31%, P < 0.00001). HR for death in the CTh alone group was 3.73 (95% CI = 1.95 - 7.13). The CR (P = 0.01), DFS (P = 0.01) and OS (P = 0.03) rates were significantly better for patients receiving a RT dose of > or =4500 cGy. HR in the subgroup that received a RT dose of <4500 cGy was 2.51 (95% CI = 1.04 - 6.06). These results suggest that combined modality treatment, comprising of CTh and RT (with an RT dose of > or =4500 cGy), results in satisfactory outcome in patients with this rare neoplasm.

Primary non-Hodgkin's lymphoma of the nasopharynx: prognostic factors and outcome of 113 Indian patients.

The goal of this study was to evaluate the efficacy of temporary interstitial brachytherapy (BRT) for patients undergoing combined modality management of soft tissue sarcomas (STS).

Perioperative interstitial brachytherapy for soft tissue sarcomas: prognostic factors and long-term results of 155 patients.

To evaluate the efficacy of interstitial brachytherapy (BRT) in children undergoing combined modality treatment for soft tissue sarcomas (STS).

Interstitial brachytherapy for childhood soft tissue sarcoma.

The purpose was to evaluate the prognostic factors and treatment outcome of Indian patients with primary diffuse large B-cell lymphoma (DLBCL) of the tonsil treated at a single institution.

Primary diffuse large B-cell lymphoma of the tonsil: is a higher radiotherapy dose required?

To evaluate the efficacy of intensity-modulated radiotherapy (IMRT) in reducing the acute toxicities associated with conventional RT (CRT) in children with nasopharyngeal carcinoma.

Nasopharyngeal carcinoma in children: comparison of conventional and intensity-modulated radiotherapy.

To report dosimetry and outcome in a case of early stage carcinoma of external ear (T1N0M0) treated with radical radiotherapy alone using a combination of external beam radiotherapy (EBRT) and intracavitary irradiation with a high-dose-rate (HDR) (192)Ir remote afterloading system.

High-dose-rate brachytherapy boost for carcinoma of external auditory canal.

To evaluate the prognostic factors and treatment outcome of patients with Askin-Rosai tumor of the chest wall treated at a single institution.

Prognostic factors and outcome in Askin-Rosai tumor: a review of 104 patients.

Stimulated Brillouin interaction between sound and light, known to be the strongest optical nonlinearity common to all amorphous and crystalline dielectrics, has been widely studied in fibres and bulk materials but rarely in optical microresonators. The possibility of experimentally extending this principle to excite mechanical resonances in photonic microsystems, for sensing and frequency reference applications, has remained largely unexplored. The challenge lies in the fact that microresonators inherently have large free spectral range, whereas the phase-matching considerations for the Brillouin process require optical modes of nearby frequencies but with different wave vectors. Here we rely on high-order transverse optical modes to relax this limitation and report the experimental excitation of mechanical resonances ranging from 49 to 1,400 MHz by using forward Brillouin scattering. These natural mechanical resonances are excited in ∼100 μm silica microspheres, and are of a surface-acoustic whispering-gallery type.

Stimulated optomechanical excitation of surface acoustic waves in a microdevice.

Stimulated Brillouin scattering recently allowed experimental excitation of surface acoustic resonances in micro-devices, enabling vibration at rates in the range of 50 MHz to 12 GHz. The experimental availability of such mechanical whispering gallery modes in photonic-MEMS raises questions on their structure and spectral distribution. Here we calculate the form and frequency of such vibrational surface whispering gallery modes, revealing diverse types of surface vibrations including longitudinal, transverse, and Rayleigh-type deformations. We parametrically investigate these various modes by changing their orders in the azimuthal, radial, and polar directions to reveal different vibrational structures including mechanical resonances that are localized near the interface with the environment where they can sense changes in the surroundings.

Surface optomechanics: calculating optically excited acoustical whispering gallery modes in microspheres.

Cavity optomechanics allows the parametric coupling of phonon- and photon-modes in microresonators and is presently investigated in a broad variety of solid-state systems. Optomechanics with superfluids has been proposed as a path towards ultra-low optical- and mechanical-dissipation. However, there have been no optomechanics experiments reported with non-solid phases of matter. Direct liquid immersion of optomechanics experiments is challenging, as the acoustic energy simply leaks out to the higher-impedance liquid surrounding the device. Here we confine liquids within hollow resonators to circumvent this issue and to enable optical excitation of mechanical whispering-gallery modes at frequencies ranging from 2 to 11,000 MHz. Our device enables optomechanical investigation with liquids, while light is conventionally coupled from the outer dry side of the capillary, and liquids are provided by means of a standard microfluidic inlet.

Brillouin cavity optomechanics with microfluidic devices.

Recently, the first microfluidic optomechanical device was demonstrated, capable of operating with non-solid states of matter (viscous fluids, bioanalytes). These devices exhibit optomechanical oscillation in both the 10-20 MHz and 10-12 GHz regimes, driven by radiation pressure (RP) and stimulated Brillouin scattering (SBS) respectively. In this work, we experimentally investigate aerostatic tuning of these hollow-shell oscillators, enabled by geometry, stress, and temperature effects. We also demonstrate for the first time the simultaneous actuation of RP-induced breathing mechanical modes and SBS-induced whispering gallery acoustic modes, through a single pump laser. Our result is a step towards completely self-referenced optomechanical sensor technologies.

Gaurav Bahl

Mechanical Science and Engineering

University of Illinois at Urbana-Champaign

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Gaurav Bahl

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Mechanical Science and Engineering

University of Illinois at Urbana-Champaign

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Mechanical Science and Engineering