Frequency Response Bandwidth Calibration of High Speed Photodetector Using Frequency-Stabilized Laser by Optical Heterodyne Technique

2014 ◽  
Vol 644-650 ◽  
pp. 1031-1034
Author(s):  
Nan Xu ◽  
Jian Wei Li ◽  
Jian Li ◽  
Zhi Xin Zhang
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Beat Frequency ◽  
Tunable Laser ◽  
Laser Source ◽  
Response Measurement ◽  
System A ◽  
Response Bandwidth ◽  
Heterodyne Technique ◽  
Frequency Stabilized Laser

In this paper, frequency-stabilized laser technology is introduced into photodetector frequency response measurement system. A 1531nm frequency-stabilized laser fulfilled by acetylene saturated absorption is employed to produce coherent light with a tunable laser source, gaining stable beat frequency light that reaches as high as several hundred ghz, fulfilling measurement of 40ghz high-speed photodetector frequency response bandwidth, and lowering impacts caused by instability of light frequency. In addition, measurement uncertainty analysis is conducted, which is better than 7 %(k=2).

Intercellular communication between ciliated cells in culture

1988 ◽  
Vol 254 (1) ◽  
pp. C63-C74 ◽  
Author(s):  
M. J. Sanderson ◽  
I. Chow ◽  
E. R. Dirksen
Keyword(s):  
Frequency Response ◽  
Mechanical Stimulation ◽  
Intercellular Communication ◽  
High Speed ◽  
Beat Frequency ◽  
Computer Assisted ◽  
Image Analysis System ◽  
Ciliated Cells ◽  
Short Delay ◽  
Similar Frequency

Cultured mammalian ciliated cells from the respiratory tract respond to mechanical stimulation of their cell surface by displaying a rapid transient increase in beat frequency. Surrounding adjacent and more distal neighboring ciliated cells display a similar frequency response after a short delay that is proportional to their distance from the stimulated cell. To characterize the progression of this communicated response we developed an automated computer-assisted image-analysis system to examine high-speed films of responding cells. Transmission of the frequency response between cells occurs at 0.63 cells/s at 25 degrees C and 1.54 cells/s at 37 degrees C. We have also confirmed that gap junctions exist between cells in both epithelial explants and outgrowths and that adjacent or nonadjacent ciliated, as well as nonciliated, cells are electrically coupled. We postulate that mechanical stimulation and intercellular communication provide a mechanism to regulate beat frequency between ciliated cells in order to facilitate efficient ciliary function and mucus transport.

Simultaneous Time-Frequency Control of Multi-Dimensional Micro-Milling Instability

2012 ◽  
Author(s):  
Meng-Kun Liu ◽  
Eric B. Halfmann ◽  
C. Steve Suh
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Frequency Control ◽  
External Perturbation ◽  
Micro Milling ◽  
Time Frequency ◽  
System A ◽  
Control Concept ◽  
The Time Domain ◽  
Tool Damage

A novel control concept is presented for the online control of a high-speed micro-milling model system in the time and frequency domains concurrently. Micro-milling response at high-speed is highly sensitive to machining condition and external perturbation, easily deteriorating from bifurcation to chaos. When losing stability, milling time response is no longer periodic and the frequency response becomes broadband, rendering aberrational tool chatter and probable tool damage. The controller effectively mitigates the nonlinear vibration of the tool in the time domain and at the same time confines the frequency response from expanding and becoming chaotically broadband. The simultaneous time-frequency control is achieved through manipulating wavelet coefficients, thus not limited by the increasing bandwidth of the chaotic system — a fundamental restraint that deprives contemporary controller designs of validity and effectiveness. The feedforward feature of the control concept prevents errors from re-entering the control loop and inadvertently perturbing the sensitive micro-milling system. Because neither closed-form nor linearization is required, the innate, genuine features of the micro-milling response are faithfully retained.

scholarly journals Design for a Highly Stable Laser Source Based on the Error Model of High-Speed High-Resolution Heterodyne Interferometers

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1083
Author(s):  
Hongxing Yang ◽  
Ziqi Yin ◽  
Ruitao Yang ◽  
Pengcheng Hu ◽  
Jing Li ◽  
...  
Keyword(s):  
Measurement Error ◽  
High Resolution ◽  
High Speed ◽  
Beat Frequency ◽  
Error Model ◽  
Laser Source ◽  
Measurement Error Model ◽  
High Resolution Measurement ◽  
Resolution Measurement ◽  
The Impact

Heterodyne interferometers with two opposite Doppler shift interference signals have been proposed for high-resolution measurement with high measurement speed, which can be used in the background of high-speed high-resolution measurement. However, a measurement error model for high-speed high-resolution heterodyne interferometers (HSHR-HIs) has not yet been proposed. We established a HSHR-HI measurement error model, analyzed the influence of beat frequency stability with a simplified optical structure, and then designed an offset-locked dual-frequency laser source with a digital control system to reduce the impact of beat frequency drift. Experiments were used to verify the correction of the measurement error model and the validity of the laser source. The results show that the new laser source has a maximum beat frequency range of 45 MHz, which shows the improvements in the measuring speed and resolution.

THE PARALLEL CRANK-ROCKER FLAPPING MECHANISM: AN INSECT-INSPIRED DESIGN FOR MICRO AIR VEHICLES

2007 ◽  
Vol 04 (04) ◽  
pp. 625-643 ◽  
Author(s):  
ANDREW T. CONN ◽  
STUART C. BURGESS ◽  
SENG LING CHUNG
Keyword(s):  
High Speed ◽  
Beat Frequency ◽  
Unsteady Aerodynamics ◽  
Micro Air Vehicles ◽  
Indoor Environments ◽  
Insect Wing ◽  
Wing Kinematics ◽  
System A ◽  
Flying Robot ◽  
Flapping Mechanism

This paper presents a novel micro air vehicle (MAV) design that seeks to reproduce the unsteady aerodynamics of insects in their natural flight. The challenge of developing an MAV capable of hovering and maneuvering through indoor environments has led to bio-inspired flapping propulsion being considered instead of conventional fixed or rotary winged flight. Insects greatly outperform these conventional flight platforms by exploiting several unsteady aerodynamic phenomena. Therefore, reproducing insect aerodynamics by mimicking their complex wing kinematics with a miniature flying robot has significant benefits in terms of flight performance. However, insect wing kinematics are extremely complex and replicating them requires optimal design of the actuation and flapping mechanism system. A novel flapping mechanism based on parallel crank-rockers has been designed that accurately reproduces the wing kinematics employed by insects and also offers control for flight maneuvers. The mechanism has been developed into an experimental prototype with MAV scale wings (75 mm long). High-speed camera footage of the non-airborne prototype showed that its wing kinematics closely matched desired values, but that the wing beat frequency of 5.6 Hz was below the predicted value of 15 Hz. Aerodynamic testing of the prototype in hovering conditions was completed using a load cell and the mean lift force at the maximum power output was measured to be 23.8 mN.

Beat-Frequency Locking of Ultradense WDM Channels Using a Tunable Laser Source

2004 ◽  
Vol 16 (5) ◽  
pp. 1382-1384 ◽  
Author(s):  
S.-Y. Kim ◽  
S.-W. Huh ◽  
S.-H. Lee ◽  
K.-H. Seo ◽  
J.-S. Lee
Keyword(s):  
Beat Frequency ◽  
Tunable Laser ◽  
Laser Source ◽  
Frequency Locking ◽  
Tunable Laser Source

High-speed photodetector characterization using tunable laser by optical heterodyne technique

2005 ◽  
Author(s):  
Haisheng San ◽  
Jimin Wen ◽  
Liang Xie ◽  
Ninghua Zhu ◽  
Boxue Feng
Keyword(s):  
High Speed ◽  
Tunable Laser ◽  
Optical Heterodyne ◽  
Heterodyne Technique

scholarly journals Precise Optical Modulation and Its Application to Optoelectronic Device Measurement

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 160
Author(s):  
Tetsuya Kawanishi
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Extinction Ratio ◽  
Optoelectronic Devices ◽  
Optical Filters ◽  
Optical Modulation ◽  
Optical Frequency ◽  
Optical Modulators ◽  
Response Measurement ◽  
Mach Zehnder Modulator

Optoelectronic devices which play important roles in high-speed optical fiber networks can offer effective measurement methods for optoelectronic devices including optical modulators and photodetectors. Precise optical signal modulation is required for measurement applications. This paper focuses on high-speed and precise optical modulation devices and their application to device measurement. Optical modulators using electro-optic effect offers precise control of lightwaves for wideband signals. As examples, this paper describes frequency response measurement of photodetectors using high-precision amplitude modulation and wavelength domain measurement of optical filters using fast optical frequency sweep. Precise and high-speed modulation can be achieved by active trimming which compensates device structure imbalance due to fabrication error, where preciseness can be described by on-off extinction ratio. A Mach-Zehnder modulator with sub Mach-Zehnder interferometors can offer high extinction-ratio optical intensity modulation, which can be used for precise optoelectronic frequency response measurement. Precise modulation would be also useful for multi-level modulation schemes. To investigate impact of finite extinction ratio on optical modulation, duobinary modulation with small signal operation was demonstrated. For optical frequency domain analysis, single sideband modulation, which shifts optical frequency, can be used for generation of stimulus signals. Rapid measurement of optical filters was performed by using an optical sweeper consisting of an integrated Mach-Zehnder modulator for optical frequency control and an arbitrary waveform generator for generation of a source frequency chirp signal.

scholarly journals Frequency response measurement of high-speed photodiodes based on a photonic sampling of an envelope-modulated microwave subcarrier

2021 ◽  
Vol 29 (7) ◽  
pp. 9836
Author(s):  
Mengke Wang ◽  
Shangjian Zhang ◽  
Ying Xu ◽  
Yutong He ◽  
Yali Zhang ◽  
...  
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Response Measurement ◽  
Frequency Response Measurement ◽  
Photonic Sampling
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