Generation of a chirp-free optical pulse train with tunable pulse width based on a polarization modulator and an intensity modulator

2009 ◽  
Vol 34 (14) ◽  
pp. 2186 ◽  
Author(s):  
Shilong Pan ◽  
Jianping Yao
Keyword(s):  
Pulse Train ◽  
Pulse Width ◽  
Optical Pulse ◽  
Intensity Modulator ◽  
Polarization Modulator

scholarly journals Effects of electrical stimulation on isolated rodent gastric smooth muscle cells evaluated via a joint computational simulation and experimental approach

2009 ◽  
Vol 297 (4) ◽  
pp. G672-G680 ◽  
Author(s):  
P. Du ◽  
S. Li ◽  
G. O'Grady ◽  
L. K. Cheng ◽  
A. J. Pullan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Pulse Train ◽  
Pulse Width ◽  
Computational Simulation ◽  
Minimum Energy ◽  
Experimental Studies ◽  
Single Pulse ◽  
Plateau Phase ◽  
Wide Range

Gastric electrical stimulation (GES) involves the delivery of electrical impulses to the stomach for therapeutic purposes. New GES protocols are needed that are optimized for improved motility outcomes and energy efficiency. In this study, a biophysically based smooth muscle cell (SMC) model was modified on the basis of experimental data and employed in conjunction with experimental studies to define the effects of a large range of GES protocols on individual SMCs. For the validation studies, rat gastric SMCs were isolated and subjected to patch-clamp analysis during stimulation. Experimental results were in satisfactory agreement with simulation results. The results define the effects of a wide range of GES parameters (pulse width, amplitude, and pulse-train frequency) on isolated SMCs. The minimum pulse width required to invoke a supramechanical threshold response from SMCs (defined at −30 mV) was 65 ms (at 250-pA amplitude). The minimum amplitude required to invoke this threshold was 75 pA (at 1,000-ms pulse width). The amplitude of the invoked response beyond this threshold was proportional to the stimulation amplitude. A high-frequency train of stimuli (40 Hz; 10 ms, 150 pA) could invoke and maintain the SMC plateau phase while requiring 60% less power and accruing ∼30% less intracellular Ca2+ concentration during the plateau phase than a comparable single-pulse protocol could in a demonstrated example. Validated computational simulations are an effective strategy for efficiently identifying effective minimum-energy GES protocols, and pulse-train protocols may also help to reduce the power consumption of future GES devices.

Optical pulse train repetition rate and envelope control based on the optical fourier transform

2009 ◽  
Author(s):  
Santiago Tainta ◽  
Maria J. Erro ◽  
Maria J. Garde ◽  
Waldimar Amaya ◽  
Salvador Sales ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Repetition Rate ◽  
Pulse Train ◽  
Optical Pulse ◽  
Optical Fourier Transform

scholarly journals Quantitative characteristic of phase signal with changed pulse in the coherent PHI-OTDR system

2020 ◽  
Author(s):  
Zhen Zhong ◽  
Xuping Zhang
Keyword(s):  
Pulse Width ◽  
Peak Power ◽  
Optical Pulse ◽  
Quantitative Characteristic ◽  
Maximum Amplitude ◽  
Observation Point ◽  
Electrical Signal ◽  
Rayleigh Backscattering ◽  
Phase Signal ◽  
Measured Phase

In the coherent PHI-OTDR system, the phase signal is retrieved based on the reference point and the observation point which are off and closer to the two sides of step of the phase change. In the experiment, the optical pulse with the changed peak power, width or shape is injected into the fiber for interrogating the change of the quantitative characteristic of the measured phase signal. When the pulse width is fixed at 200 ns and its peak power is adjusted from 14 dBm to -23 dBm, the amplitude is slightly increased from 17.3575 rad to 17.4411 rad as long as the Rayleigh backscattering signal can be found in the electrical signal. Changing the pulse width from 260 ns to 80 ns when the peak power is fixed at 14 dBm, the maximum amplitude and the minimum amplitude of the measured phase signal are 17.4625 rad to 17.4509 rad, respectively. When the arbitrary shape of the optical pulse generated from the MZI structure with a changed delay fiber from 3 m to 6 m, the amplitude varies from 17.4558 rad to 17.4819 rad. For every measurement, the change of frequency is also small. And the small value of standard deviation supports the accuracy of the measurement. All the measurements show that the changed pulse nearly has no impact on the quantitative characteristic of the measured phase signal in the coherent PHI-OTDR system. Moreover, we also find that the phase signal of external event can be correctly extracted as long as the Rayleigh backscattering signal can be detected.<br>

Fast All-Optical Pulse Train Modulation by Silicon Photonic Crystal Nanocavities

2006 ◽  
Author(s):  
Takasumi Tanabe ◽  
Koji Yamada ◽  
Katsuhiko Nishiguchi ◽  
Eiichi Kuramochi ◽  
Akihiko Shinya ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Pulse Train ◽  
Optical Pulse ◽  
Silicon Photonic ◽  
All Optical

Optical Pulse Width Modulated Multilevel Transmission in CIS-Based VLC

2017 ◽  
Vol 29 (15) ◽  
pp. 1257-1260 ◽  
Author(s):  
Joon-Woo Lee ◽  
Se-Hoon Yang ◽  
Sang-Kook Han
Keyword(s):  
Pulse Width ◽  
Optical Pulse ◽  
Pulse Width Modulated ◽  
In Cis
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