scholarly journals Analysis of the dynamic behavior and short-pulse modulation scheme for laterally coupled diode lasers

2001 ◽  
Vol 7 (2) ◽  
pp. 192-200 ◽  
Author(s):  
H. Lamela ◽  
M. Leones ◽  
G. Carpintero ◽  
C. Simmendinger ◽  
O. Hess
Keyword(s):  
Dynamic Behavior ◽  
Short Pulse ◽  
Diode Lasers ◽  
Modulation Scheme ◽  
Pulse Modulation

scholarly journals Static Ice Pressure Measuring System Based on Fiber Loop Ring-Down Spectroscopy and FPGA

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5927
Author(s):  
Xiao Deng ◽  
Dingrui Wang ◽  
Lipeng Pan ◽  
Li Zhang ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Optical Fiber Sensor ◽  
Temperature Stability ◽  
Field Application ◽  
Measuring System ◽  
Modulation Scheme ◽  
In Situ Observation ◽  
Pulse Modulation ◽  
Loop Ring ◽  
Ice Pressure ◽  
Fiber Loop

Hydraulic engineering built in the cold region, such as reservoirs and hydropower stations, is often threatened by static ice pressure from nature. Therefore, it is of vital significance to research the pressure variation in the growth and melting processes of the ice layer for the design and protection of hydraulic structures in cold regions. This paper introduces an optical fiber sensor system based on the fiber loop ring-down spectroscopy technology and field-programmable gate array (FPGA) pulse modulation technology. An electro-optic modulation scheme that relied on FPGA to generate optical pulses with adjustable pulse width and period is proposed, which is more suitable for the in-situ observation. In addition, the temperature stability and repeatability of the system are also discussed. This system was applied to the real-time detection of static ice pressure on the sidewall and bottom of the polyvinyl chloride (PVC) pipe during the ice growth and melting processes. The results indicate that the system has favorable stability and sensitivity, and the relationship obtained between the static ice pressure and temperature could provide some references for the field application in the future.

Combined pulse-modulation scheme for feedback systems

1969 ◽  
Vol 5 (18) ◽  
pp. 436 ◽  
Author(s):  
M.A. Pai ◽  
M.S. Varadarajan
Keyword(s):  
Modulation Scheme ◽  
Feedback Systems ◽  
Pulse Modulation

Short-pulse modulation of gallium-arsenide lasers with TRAPATT diodes

1973 ◽  
Vol 9 (7) ◽  
pp. 166 ◽  
Author(s):  
J.E. Carroll ◽  
J.G. Farrington
Keyword(s):  
Gallium Arsenide ◽  
Short Pulse ◽  
Pulse Modulation

scholarly journals Step-Pulse Modulation of Gain-Switched Semiconductor Pulsed Laser

2019 ◽  
Vol 9 (3) ◽  
pp. 602 ◽  
Author(s):  
Bin Li ◽  
Changyan Sun ◽  
Yun Ling ◽  
Heng Zhou ◽  
Kun Qiu
Keyword(s):  
Semiconductor Laser ◽  
Peak Power ◽  
Short Pulse ◽  
Extinction Ratio ◽  
Pulse Signal ◽  
Single Pulse ◽  
Single Mode ◽  
Output Pulse ◽  
Time Domain Reflectometry ◽  
Pulse Modulation

To improve the peak power and extinction ratio and produce ultra-short pulses, a novel approach is presented in this paper offers a highly effective modulated method for a gain-switched semiconductor laser by using step-pulse signal modulation. For the purpose of single pulse output, then the effects on the output from the gain-switched semiconductor laser are studied by simulating single mode rate equation when changing the amplitude and width of the modulated signal. The results show that the proposed method can effectively accelerate the accumulation speed of the population inversion and we can acquire the output pulse with higher peak power and shorter width. Compared with the traditional rectangular wave modulation, this method is advantageous to obtain a high gain switching effect by increasing the second modulation current and reduce the pulse width to saturation at the best working point. It can be incorporated as a practical and cost-effective approach for many fields which need high extinction ratio short pulse, such as the optical time domain reflectometry.

scholarly journals Underwater laser communication with sloped pulse modulation in turbid water

2019 ◽  
Vol 15 (3) ◽  
pp. 155014771983787 ◽  
Author(s):  
Taewoong Kang ◽  
Kiman Kim ◽  
Serim Kim ◽  
Donghun Lee
Keyword(s):  
Forward Error Correction ◽  
Transmission Rate ◽  
Water Channel ◽  
Blue Laser ◽  
Laser Communication ◽  
Modulation Scheme ◽  
Communication Link ◽  
Turbid Water ◽  
Pulse Modulation ◽  
Band Limited

In this article, we propose the demonstration of an underwater wireless laser communication link operating at data rates of up to 100 Mbps over a band-limited turbid water channel using a modified pulse position modulation scheme with a sloped pulse. The communication link uses an avalanche photodiode module as the receiver. The bit error rate of a 5.4 × 10−6 by 450-nm blue laser diode in turbid water with 1.4 Nephelometric Turbidity Unit was below the forward error correction limit. Our demonstrated underwater wireless laser communication system is simple to use and maintains a high data transmission rate.

Performance Analysis of New Hybrid Pulse Modulation Scheme in Optical Wireless System

2015 ◽  
Vol 35 (7) ◽  
pp. 0706004
Author(s):  
刘宏展 Liu Hongzhan ◽  
廖仁波 Liao Renbo ◽  
孙建锋 Sun Jianfeng ◽  
刘立人 Liu Liren
Keyword(s):  
Performance Analysis ◽  
Modulation Scheme ◽  
Optical Wireless ◽  
Pulse Modulation ◽  
Wireless System
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