Numerical simulations of the spatial-temporal dynamics and mode-locking in a waveguide array laser cavity

2009 ◽  
Author(s):  
Colin McGrath ◽  
J. Nathan Kutz
Keyword(s):  
Numerical Simulations ◽  
Temporal Dynamics ◽  
Laser Cavity ◽  
Mode Locking ◽  
Waveguide Array

ON MODELING THE GROWTH DYNAMICS OF A STAGE STRUCTURED POPULATION

2013 ◽  
Vol 06 (06) ◽  
pp. 1350039 ◽  
Author(s):  
GIUSEPPE BUFFONI ◽  
SARA PASQUALI
Keyword(s):  
Numerical Simulations ◽  
Temporal Dynamics ◽  
Growth Dynamics ◽  
Biological Processes ◽  
Dispersion Models ◽  
Development Models ◽  
Regression Effects ◽  
Pelagic Copepod ◽  
Structured Population ◽  
Lagrangian Modeling

A Lagrangian modeling approach is applied to the numerical simulation of the temporal dynamics of a stage-structured population. The growth dynamics is determined only by the main biological processes: development of an individual, mortality, reproduction. Different approaches in modeling the development process of an individual are implemented: stochastic advection-diffusion models (backward–forward dispersion models), and stochastic development models where regression effects, defined as negative development on the status of an individual, are forbidden (forward dispersion models). Some properties of the residence times of an individual in a stage are investigated: in particular, their role in the calibration of the development models and in the estimation of some parameters introduced in the model equation. As a study case a multi-stage pelagic copepod population is considered. Trying to separate the effects of the main biological processes on the temporal dynamics, numerical simulations have been carried out in some idealized situations: first only the development of the individuals, neglecting mortality and reproduction, is considered; then the mortality process is introduced, and finally both the mortality and reproduction processes. The results of the numerical simulations, are compared and discussed.

scholarly journals Breathing dissipative solitons in mode-locked fiber lasers

2019 ◽  
Vol 5 (11) ◽  
pp. eaax1110 ◽  
Author(s):  
Junsong Peng ◽  
Sonia Boscolo ◽  
Zihan Zhao ◽  
Heping Zeng
Keyword(s):  
Ultrafast Lasers ◽  
Laser Cavity ◽  
Mode Locking ◽  
Oscillatory Behavior ◽  
Dissipative Systems ◽  
Stationary Mode ◽  
Practical Applications ◽  
Fast Detection ◽  
Dissipative Solitons ◽  
Laser Sources

Dissipative solitons are self-localized coherent structures arising from the balance between energy supply and dissipation. Besides stationary dissipative solitons, there are dynamical ones exhibiting oscillatory behavior, known as breathing dissipative solitons. Substantial interest in breathing dissipative solitons is driven by both their fundamental importance in nonlinear science and their practical applications, such as in spectroscopy. Yet, the observation of breathers has been mainly restricted to microresonator platforms. Here, we generate breathers in a mode-locked fiber laser. They exist in the laser cavity under the pump threshold of stationary mode locking. Using fast detection, we are able to observe the temporal and spectral evolutions of the breathers in real time. Breathing soliton molecules are also observed. Breathers introduce a new regime of mode locking into ultrafast lasers. Our findings may contribute to the design of advanced laser sources and open up new possibilities of generating breathers in various dissipative systems.

Optimizing waveguide array mode-locking for high-power fiber lasers

2009 ◽  
Author(s):  
Brandon G. Bale ◽  
J. Nathan Kutz ◽  
Bjorn Sandstede
Keyword(s):  
High Power ◽  
Fiber Lasers ◽  
Mode Locking ◽  
Waveguide Array

scholarly journals Distributed Kerr Lens Mode-Locked Yb:YAG Thin-Disk Oscillator

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Jinwei Zhang ◽  
Markus Pӧtzlberger ◽  
Qing Wang ◽  
Jonathan Brons ◽  
Marcus Seidel ◽  
...  
Keyword(s):  
High Power ◽  
Average Power ◽  
Ultrashort Pulses ◽  
Laser Cavity ◽  
Mode Locking ◽  
Gain Medium ◽  
Thin Disk ◽  
Narrow Bandwidth ◽  
Cavity Modes ◽  
High Power Output

Ultrafast laser oscillators are indispensable tools for diverse applications in scientific research and industry. When the phases of the longitudinal laser cavity modes are locked, pulses as short as a few femtoseconds can be generated. As most high-power oscillators are based on narrow-bandwidth materials, the achievable duration for high-power output is usually limited. Here, we present a distributed Kerr lens mode-locked Yb:YAG thin-disk oscillator which generates sub-50 fs pulses with spectral widths far broader than the emission bandwidth of the gain medium at full width at half maximum. Simulations were also carried out, indicating good qualitative agreement with the experimental results. Our proof-of-concept study shows that this new mode-locking technique is pulse energy and average power scalable and applicable to other types of gain media, which may lead to new records in the generation of ultrashort pulses.

scholarly journals Investigating the Threshold Conditions of Air Breakdown with Mode-Locked Q-Switched Laser Pulses, and the Temporal Dynamics of Induced Plasma with Self-Scattering Phenomenon

2021 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Kai-Ting Yen ◽  
Chih-Hung Wu ◽  
Pin-Hsun Wang ◽  
Pi-Hui Tuan ◽  
Kuan-Wei Su
Keyword(s):  
High Speed ◽  
Temporal Dynamics ◽  
Laser Pulses ◽  
Mode Locking ◽  
Excitation Pulse ◽  
Plasma Radiation ◽  
Breakdown Threshold ◽  
Scattering Rate ◽  
Threshold Conditions ◽  
Air Breakdown

A Q-switched Nd:YAG laser with mode-locked modulations is utilized to explore the laser-induced air breakdown. The various modulation depths of the mode-locking within the Q-switched pulse can be utilized to investigate the threshold conditions. With the GHz high-speed detectors to accurately measure the temporal pulse shape pulse by pulse, it is verified that the air breakdown threshold is crucially determined by the peak-power density instead of the energy density from the statistic results, especially for mode-locked Q-switched lasers. The stability of the system for laser-induced breakdown can be evaluated by threshold width through fitting the statistical result. Otherwise, by measuring the temporal characteristics of the excitation pulse and the induced plasma, it is further found that the plasma radiation displays a few-nanoseconds time delay to the excitation pulse and shows a decaying tail to be 10 times longer than the plasma build-up time. Moreover, the incident laser pulse is observed to be self-scattered by the air breakdown, and a rapidly modulated scattering rate is found with a slight delay time to the excitation mode-locked subpulse modulations.

scholarly journals Quasi-Distributed Active-Mode-Locking Laser Interrogation with Multiple Partially Reflecting Segment Sensors

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4128
Author(s):  
Chang Park ◽  
Gyeong Kim ◽  
Suck Hong ◽  
Hwi Lee ◽  
Chang-Seok Kim
Keyword(s):  
Laser Cavity ◽  
Length Change ◽  
Mode Locking ◽  
Segment Length ◽  
Length Variation ◽  
Active Mode ◽  
Distributed Sensor ◽  
Fabry Perot ◽  
New Type ◽  
The Difference

A new type of quasi-distributed sensor system is implemented using an active mode locking (AML) laser cavity with multiple partially reflecting segments. The mode locking frequency of the AML laser is linearly proportional to the overall lasing cavity length. To implement multiple resonators having multiple reflection points installed in a sensing fiber, two types of partial reflectors (PRs) are implemented for an in-line configuration, one with fiber Bragg grating and the other with a fiber Fabry–Perot interferometer. Since the laser has oscillated only when the modulation frequencies for the mode locking frequency match with the corresponding resonator lengths, it is possible to read the multiple partially reflecting segments along the sensing fiber. The difference between two corresponding mode locking frequencies is changing proportionally with the segment length variation between two PRs upon strain application. The segment length change caused by the applied strain can be successfully measured with a linear sensitivity between mode locking frequency and displacement, linearity over 0.99, and spatial position resolution below meter order.

Mode-locking by an intracavity plasma. Part II. Experimental results

1982 ◽  
Vol 60 (1) ◽  
pp. 77-87
Author(s):  
M. Piché ◽  
P. A. Bélanger
Keyword(s):  
Laser Light ◽  
Short Pulse ◽  
Critical Role ◽  
Laser Cavity ◽  
Mode Locking ◽  
Laser Mode ◽  
Pulse Trains ◽  
Frequency Shifter ◽  
Gas Breakdown ◽  
The Relationship

The results of an experimental investigation of TEA-CO2 laser mode-locking by an intracavity plasma are described in this paper. The observations evidence the critical role played by the plasma switching process; complete mode-locking was consecutive to a fast cutoff of the gain-switched laser pulse. The laser beam was focussed by the plasma at the instant of gas breakdown. The short pulse trains were depolarized, even though the gain-switched pulse producing the plasma was plane polarized. The plasma was shown to both reflect and transmit laser light by moving its relative position in the laser cavity. The results are discussed in terms of a model involving the combination of an amplitude shutter and a frequency shifter. We establish the relationship between our experiment and similar ones reported in the literature.

Sign in / Sign up

Export Citation Format

Share Document