Frequency Noise Reduction of Integrated Laser Source with On-Chip Optical Feedback

2017 ◽  
Author(s):  
Bowen Song ◽  
Keisuke Kojima ◽  
Sergio Pinna ◽  
Toshiaki Koike-Akino ◽  
Bingnan Wang ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Optical Feedback ◽  
Laser Source ◽  
Frequency Noise ◽  
On Chip

Noise Reduction of Integrated Laser Source with On-Chip Optical Feedback

2017 ◽  
Author(s):  
Bowen Song ◽  
Keisuke Kojima ◽  
Sergio Pinna ◽  
Toshiaki Koike-Akino ◽  
Bingnan Wang ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Optical Feedback ◽  
Laser Source ◽  
On Chip

scholarly journals Avoiding transduction-induced heating in suspended microchannel resonators using piezoelectricity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Damien Maillard ◽  
Annalisa De Pastina ◽  
Amir Musa Abazari ◽  
Luis Guillermo Villanueva
Keyword(s):  
Resonance Frequency ◽  
Frequency Shift ◽  
Laser Doppler Vibrometer ◽  
Laser Source ◽  
Frequency Noise ◽  
Resonance Frequency Shift ◽  
Suspended Microchannel Resonators ◽  
On Chip ◽  
Biological Entities ◽  
Microchannel Resonators

AbstractCalorimetry of single biological entities remains elusive. Suspended microchannel resonators (SMRs) offer excellent performance for real-time detection of various analytes and could hold the key to unlocking pico-calorimetry experiments. However, the typical readout techniques for SMRs are optical-based, and significant heat is dissipated in the sensor, altering the measurement and worsening the frequency noise. In this manuscript, we demonstrate for the first time full on-chip piezoelectric transduction of SMRs on which we focus a laser Doppler vibrometer to analyze its effect. We demonstrate that suddenly applying the laser to a water-filled SMR causes a resonance frequency shift, which we attribute to a local increase in temperature. When the procedure is repeated at increasing flow rates, the resonance frequency shift diminishes, indicating that convection plays an important role in cooling down the device and dissipating the heat induced by the laser. We also show that the frequency stability of the device is degraded by the laser source. In comparison to an optical readout scheme, a low-dissipative transduction method such as piezoelectricity shows greater potential to capture the thermal properties of single entities.

10-times Frequency Noise Reduction of a Tuneable Semiconductor Laser via an Incoherent Optical-Feedback

2016 ◽  
Author(s):  
Aaron Albores-Mejia ◽  
Toshimitsu Kaneko ◽  
Katsumi Uesaka ◽  
Hajime Shoji ◽  
Haruhiko Kuwatsuka
Keyword(s):  
Noise Reduction ◽  
Semiconductor Laser ◽  
Optical Feedback ◽  
Frequency Noise

Numerical study on the airfoil self-noise of three owl-based wings with the trailing-edge serrations

2021 ◽  
pp. 095441002098822
Author(s):  
Dian Li ◽  
Xiaomin Liu ◽  
Lei Wang ◽  
Fujia Hu ◽  
Guang Xi
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Numerical Study ◽  
Barn Owl ◽  
Aerodynamic Noise ◽  
Frequency Noise ◽  
Trailing Edge ◽  
Reduction Mechanisms ◽  
Trailing Edge Serrations ◽  
Bionic Airfoil

Previous publications have summarized that three special morphological structures of owl wing could reduce aerodynamic noise under low Reynolds number flows effectively. However, the coupling noise-reduction mechanism of bionic airfoil with trailing-edge serrations is poorly understood. Furthermore, while the bionic airfoil extracted from natural owl wing shows remarkable noise-reduction characteristics, the shape of the owl-based airfoils reconstructed by different researchers has some differences, which leads to diversity in the potential noise-reduction mechanisms. In this article, three kinds of owl-based airfoils with trailing-edge serrations are investigated to reveal the potential noise-reduction mechanisms, and a clean airfoil based on barn owl is utilized as a reference to make a comparison. The instantaneous flow field and sound field around the three-dimensional serrated airfoils are simulated by using incompressible large eddy simulation coupled with the FW-H equation. The results of unsteady flow field show that the flow field of Owl B exhibits stronger and wider-scale turbulent velocity fluctuation than that of other airfoils, which may be the potential reason for the greater noise generation of Owl B. The scale and magnitude of alternating mean convective velocity distribution dominates the noise-reduction effect of trailing-edge serrations. The noise-reduction characteristic of Owl C outperforms that of Barn owl, which suggests that the trailing-edge serrations can suppress vortex shedding noise of flow field effectively. The trailing-edge serrations mainly suppress the low-frequency noise of the airfoil. The trailing-edge serration can suppress turbulent noise by weakening pressure fluctuation.

scholarly journals Shape Factors in Low‐Frequency Noise Reduction

1967 ◽  
Vol 42 (5) ◽  
pp. 1202-1203
Author(s):  
J. Ronald Bailey ◽  
Franklin D. Hart
Keyword(s):  
Noise Reduction ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Shape Factors
Sign in / Sign up

Export Citation Format

Share Document