scholarly journals High-quality-factor Optical Microresonators Fabricated on Lithium Niobite Thin Film with an Electro-optical Tuning Range Spanning Over One Free Spectral Range

2020 ◽  
Author(s):  
Zhe Wang ◽  
Chaohua Wu ◽  
Zhiwei Fang ◽  
Min Wang ◽  
Jintian Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Spectral Range ◽  
Tuning Range ◽  
Free Spectral Range ◽  
Resonance Wavelength ◽  
Q Factor ◽  
High Quality ◽  
Electric Voltage ◽  
Optical Microresonators ◽  
Racetrack Resonator

We demonstrate high quality (intrinsic Q factor ~2.8×106) racetrack microresonators fabricated on lithium niobate (LN) thin film with a free spectral range (FSR) of ~86.38 pm. By integrating microelectrodes alongside the two straight arms of the racetrack resonator, the resonance wavelength around the 1550 nm can be red shifted by 92 pm when the electric voltage is raised from -100 V to 100 V. The microresonators of the tuning range spanning over a full FSR is fabricated using photolithography assisted chemo-mechanical etching (photolithography assisted chemo-mechanical etching, PLACE).

scholarly journals Narrowband and flexible perfect absorber based on a thin-film nano-resonator incorporating a dielectric overlay

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chul-Soon Park ◽  
Sang-Shin Lee
Keyword(s):  
Thin Film ◽  
Resonance Condition ◽  
Metal Layer ◽  
High Fidelity ◽  
Perfect Absorber ◽  
Q Factor ◽  
High Quality ◽  
Perfect Absorption ◽  
Narrow Bandwidth ◽  
20 Nm

Abstract We developed a flexible perfect absorber based on a thin-film nano-resonator, which consists of metal–dielectric–metal integrated with a dielectric overlay. The proposed perfect absorber exhibits a high quality (Q-)factor of ~ 33 with a narrow bandwidth of ~ 20 nm in the visible band. The resonance condition hinging on the adoption of a dielectric overlay was comprehensively explored by referring to the absorption spectra as a function of the wavelength and thicknesses of the overlay and metal. The results verified that utilizing a thicker metal layer improved the Q-factor and surface smoothness, while the presence of the overlay allowed for a relaxed tolerance during practical fabrication, in favor of high fidelity with the design. The origin of the perfect absorption pertaining to zero reflection was elucidated by referring to the optical admittance. We also explored a suite of perfect absorbers with varying thicknesses. An angle insensitive performance, which is integral to such a flexible optical device, was experimentally identified. Consequently, the proposed thin-film absorber featured an enhanced Q-factor in conjunction with a wide angle of acceptance. It is anticipated that our absorber can facilitate seminal applications encompassing advanced sensors and absorption filtering devices geared for smart camouflage and stealth.

Thermoelastic Damping Based Design, Sensitivity Study and Demonstration of a Functional Hybrid Gyroscope Resonator for High Quality Factor

2021 ◽  
Vol 29 (1) ◽  
pp. 70-96
Author(s):  
N.G. Sharma ◽  
◽  
Sundararajan T. ◽  
G.S. Singh ◽  
◽  
...  
Keyword(s):  
Thin Film ◽  
Quality Factor ◽  
Sensitivity Study ◽  
Fused Silica ◽  
High Quality Factor ◽  
Q Factor ◽  
Thermoelastic Damping ◽  
High Quality ◽  
Field Problem ◽  
Macro Scale

The most critical element of Hemispherical Resonator Gyroscope (HRG) is the high quality factor (Q-factor) mechanical resonator. This paper discusses the role of thermoelastic damping (TED) on effective Q-factor. Finite element method (FEM) is used to solve this highly coupled field problem involving vibration, solid mechanics, heat transfer and thermodynamics. The major contribution of this paper is the sensitivity analysis of the effect of material property, operating temperature and dimensions to arrive at macro scale resonator configuration. Hybrid hemispherical-cylindrical configuration is proposed by studying the performance parameters such as effective mass and angular gain.The uniqueness of the present work is the sensitivity study of ultra thin film coating (volume fraction of 0.01%), coating variations and different coating configurations. The coating can reduce the Q-factor by a few orders compared to uncoated shell. It has been found that coating material selection and coating configuration are very important factors. Another significance of the present work is the realization and detailed characterization of the hybrid fused silica resonator. Thin film gold coating is done on the 3D surfaces of the realized precision resonator. Detailed coating characterization is carried out using sophisticated instruments. Very fine balancing to the order of a few mHz is achieved after coating. Q-factor measurement of the coated resonator is carried out using LDV and achieved a few millions in the final functional hybrid resonator.

scholarly journals Free spectral range electrical tuning of a high quality on-chip microcavity

2018 ◽  
Vol 26 (26) ◽  
pp. 33649 ◽  
Author(s):  
Christiaan Bekker ◽  
Christopher G. Baker ◽  
Rachpon Kalra ◽  
Han-Hao Cheng ◽  
Bei-Bei Li ◽  
...  
Keyword(s):  
Spectral Range ◽  
Free Spectral Range ◽  
High Quality ◽  
On Chip

Low-Directivity Quasi-Monochromatic Thermal Radiation From Microcavities Covered by Thin Metal Film

2016 ◽  
Author(s):  
Asaka Kohiyama ◽  
Makoto Shimizu ◽  
Fumitada Iguchi ◽  
Hiroo Yugami
Keyword(s):  
Thin Film ◽  
Numerical Simulation ◽  
Thermal Radiation ◽  
Metal Film ◽  
Solid Angle ◽  
Thin Metal Film ◽  
Q Factor ◽  
High Quality ◽  
Quality Factor Q ◽  
Strong Confinement

Here, closed-end microcavity is proposed in which a semi-transparent metal film was formed atop microcavity. The structure shows weak angular dependence as well as quasi-monochromatic absorptance. Au is employed as material of the cavity walls and the covering thin film. Quasi-monochromatic absorption from the structure is observed in numerical simulation. High quality factor (Q factor) is obtained by strong confinement in the closed-end microcavity. Asymmetric and quasi-monochromatic absorption band with a Q factor of ∼28 at 1.85 μm was observed. This value was about 4-fold larger than that of the open-end microcavity. Additionally, the closed-end microcavity structure filled with SiO2 in cavity exhibits isotropic and quasi-monochromatic thermal radiation over a wide solid angle. This result suggests that both quasi-monochromatic and low-directivity absorptance can be realized by using this configuration.

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