scholarly journals The Path to High Q-Factors in Superconducting Accelerating Cavities: Flux Expulsion and Surface Resistance Optimization

2016 ◽  
Author(s):  
Martina Martinello
Keyword(s):  
Surface Resistance ◽  
High Q ◽  
Accelerating Cavities ◽  
Q Factors ◽  
Flux Expulsion

Optical properties of GaN Photonic Crystal Membrane Nanocavities at Blue Wavelengths

2005 ◽  
Vol 892 ◽  
Author(s):  
Yong-Seok Choi ◽  
Cedrik Meier ◽  
Rajat Sharma ◽  
Kevin Hennessy ◽  
Elaine D. Haberer ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photonic Crystal ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Light Extraction ◽  
Design Parameters ◽  
Multiple Quantum ◽  
Membrane Structures ◽  
High Q ◽  
Q Factors

AbstractWe have investigated the design parameters for high-Q photonic-crystal (PC) bandgap modes in the emission wavelengths of InGaN/GaN multiple quantum wells. We demonstrate experimental schemes to realize 2D triangular-lattice PC membrane structures, which is essential to obtain photonic bandgap (PBG) modes, and the optical properties of L7 membrane nanocavities that consist of seven missing holes in the Γ-K direction. L7 cavities show pronounced resonances with Q factors of 300 to 800 in the PBG as well as the enhancement of light extraction of the broad InGaN/GaN multiple-quantum-well emission by the 2D PBG.

High and Moderate-Level Vacuum Packaging of Vibratory MEMS

2013 ◽  
Vol 2013 (1) ◽  
pp. 000705-000710 ◽  
Author(s):  
Igor P. Prikhodko ◽  
Brenton R. Simon ◽  
Gunjana Sharma ◽  
Sergei A. Zotov ◽  
Alexander A. Trusov ◽  
...  
Keyword(s):  
Vacuum Packaging ◽  
Moderate Level ◽  
Silicon On Insulator ◽  
Quality Factors ◽  
High Q ◽  
Hermetic Sealing ◽  
Hemispherical Resonator ◽  
Q Factors ◽  
Grade Performance

We report vacuum packaging procedures for low-stress die attachment and versatile hermetic sealing of resonant MEMS. The developed in-house infrastructure allows for both high and moderate-level vacuum packaging addressing the requirements of various applications. Prototypes of 100 μm silicon-on-insulator Quadruple Mass Gyroscopes (QMGs) were packaged using the developed process with and without getters. Characterization of stand-alone packaged devices with no getters resulted in stable quality factors (Q-factors) of 1000 (corresponding to 0.5 Torr vacuum level), while devices sealed with activated getters demonstrated Q-factors of 1.2 million (below 0.1 mTorr level inside the package). Due to the high Q-factors achieved in this work, we project that the QMG used in this work can potentially reach the navigation-grade performance, potentially bridging the gap between the inertial silicon MEMS and the state-of-the-art fused quartz hemispherical resonator gyroscopes.

scholarly journals A Novel High Q Lamé-Mode Bulk Resonator with Low Bias Voltage

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 737
Author(s):  
Tianyun Wang ◽  
Zeji Chen ◽  
Qianqian Jia ◽  
Quan Yuan ◽  
Jinling Yang ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Integrated Circuit ◽  
Nonlinear Behavior ◽  
Silicon On Insulator ◽  
Transduction Efficiency ◽  
Air Gaps ◽  
High Q ◽  
Bulk Mode ◽  
Q Factors ◽  
Quality Factor Q

This work reports a novel silicon on insulator (SOI)-based high quality factor (Q factor) Lamé-mode bulk resonator which can be driven into vibration by a bias voltage as low as 3 V. A SOI-based fabrication process was developed to produce the resonators with 70 nm air gaps, which have a high resonance frequency of 51.3 MHz and high Q factors over 8000 in air and over 30,000 in vacuum. The high Q values, nano-scale air gaps, and large electrode area greatly improve the capacitive transduction efficiency, which decreases the bias voltage for the high-stiffness bulk mode resonators with high Q. The resonator showed the nonlinear behavior. The proposed resonator can be applied to construct a wireless communication system with low power consumption and integrated circuit (IC) integration.

scholarly journals Fabrication of Crystalline Microresonators of High Quality Factors with a Controllable Wedge Angle on Lithium Niobate on Insulator

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1218 ◽  
Author(s):  
Jianhao Zhang ◽  
Zhiwei Fang ◽  
Jintian Lin ◽  
Junxia Zhou ◽  
Min Wang ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Femtosecond Laser ◽  
Wedge Angle ◽  
Quality Factors ◽  
High Quality ◽  
Surface Smoothness ◽  
High Q ◽  
Q Factors

We report the fabrication of crystalline microresonators of high quality (Q) factors with a controllable wedge angle on lithium niobate on insulator (LNOI). Our technique relies on a femtosecond laser assisted chemo-mechanical polish, which allows us to achieve ultrahigh surface smoothness as critically demanded by high Q microresonator applications. We show that by refining the polish parameters, Q factors as high as 4.7 × 107 can be obtained and the wedge angle of the LNOI can be continuously tuned from 9° to 51°.

scholarly journals Internal Friction and Young's Modulus Measurements on SiO2 and Ta2O5 Films Done with an Ultra-High Q Silicon-Wafer Suspension

2015 ◽  
Vol 60 (1) ◽  
pp. 365-370 ◽  
Author(s):  
M. Granata ◽  
L. Balzarini ◽  
J. Degallaix ◽  
V. Dolique ◽  
R. Flaminio ◽  
...  
Keyword(s):  
Thin Films ◽  
Internal Friction ◽  
Silicon Wafer ◽  
Room Temperature ◽  
Suspension System ◽  
Cryogenic Temperatures ◽  
Resonant Frequencies ◽  
High Q ◽  
Key Features ◽  
Q Factors

Abstract In order to study the internal friction of thin films a nodal suspension system called GeNS (Gentle Nodal Suspension) has been developed. The key features of this system are: i) the possibility to use substrates easily available like silicon wafers; ii) extremely low excess losses coming from the suspension system which allows to measure Q factors in excess of 2×108 on 3” diameter wafers; iii) reproducibility of measurements within few percent on mechanical losses and 0.01% on resonant frequencies; iv) absence of clamping; v) the capability to operate at cryogenic temperatures. Measurements at cryogenic temperatures on SiO2 and at room temperature only on Ta2O5 films deposited on silicon are presented.

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