ANALYSIS OF TRANSIENTS AND STABILITY IN AN IDEALIZED TWO-LEVEL LASER SYSTEM

1963 ◽  
Author(s):  
J. E. Ludman
Keyword(s):  
Laser System ◽  
Level Laser

THE EFFECTS OF TEMPERATURE ON DIFFERENT LASER TRANSITIONS OF NEODYMIUM ORTHOVANADATE CRYSTAL

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Ganesan Krishnan ◽  
Noriah Bidin
Keyword(s):  
Laser Diode ◽  
Ground State ◽  
Phonon Scattering ◽  
Laser Crystal ◽  
Laser System ◽  
Temperature Dependent ◽  
Laser Transition ◽  
Level Laser ◽  
Effects Of Temperature ◽  
Terminal Level

The temperature dependence of Nd:YVO4 laser crystal pumped by laser diode emitting at 808 nm is studied within the range of 5 oC to 60 oC. The spectroscopy properties of quasi three level at 914 nm (4F3/2 - 4I 9/2) and four level at 1064 nm (4F3/2 - 4I 11/2) are characterized. The lineshape function of the transition lines were broadened as the temperature increases. The phenomenon is attributed to change in linewidth, lineshift and intensity. The linewidths for both laser transition of 914 nm and 1064 nm increases with temperature with the rate of 0.105 cm-1/oC and 0.074 cm-1/oC respectively. The peak of 914nm and 1064 nm lineshapes shifted to a longer wavelength with the rate of 3.0 pm/oC and 4.2 pm/oC respectively which correspond to same amount of lineshift. The lineshape broadening with respect to the temperature is due to one-phonon emission and Raman phonon scattering processes.  The intensities of 914 nm and 1064 nm transition lines are found to be decreased at the rate of 0.15 %/oC and 0.45 %/oC respectively due to non-radiative effects. Quasi three level laser transition is more temperature dependent because it terminal level is close to the ground state which suffers from higher phonon-ion interaction rather than four level laser system.

Optical Absorption and Emission in Rare Earth Heavy Metal Fluoride Glasses

1989 ◽  
Vol 172 ◽  
Author(s):  
R. Pafchek ◽  
J. Aniano ◽  
E. Snitzer ◽  
G. H. Sigel
Keyword(s):  
Laser System ◽  
Laser Level ◽  
Metal Fluoride ◽  
Lower Laser Level ◽  
Co Doping ◽  
Level Laser ◽  
Heavy Metal Fluoride ◽  
Preliminary Study ◽  
Level 1 ◽  
Heavy Metal Fluoride Glasses

AbstractTrivalent thulium is a 4-level laser system which operates in the 1.47μm spectral region. A tunable amplifier at this wavelength is of great interest since it falls in one of the telecommunication windows. For lasing action to occur the relatively long lived 3F4 lower laser level must be quenched to eliminate the self-terminating behavior of thulium. Rosenblatt et al. co-doped Tm and Th into a ZBLAN host to quench the 3F4 lower laser level.[1] Co-doping with Ho offers the possibility of more efficient laser operation, but it must be established whether Ho can effectively quench the lower level of Tm. This preliminary study indicated appreciable energy transfer occurred from the 3F4 level of Tm to the 5I7 level of Ho which decreased the lower laser level lifetime by as much as two orders of magnitude. The subsequent decay of the Ho ions is an issue requiring further investigation.

Multifunctional high-performance 10-J level laser system

2014 ◽  
Vol 12 (4) ◽  
pp. 041402-41406 ◽  
Author(s):  
Yujie Peng Yujie Peng ◽  
Jiangfeng Wang Jiangfeng Wang ◽  
Zhixiang Zhang Zhixiang Zhang ◽  
Dajie huang Dajie huang ◽  
Wei Fan Wei Fan ◽  
...  
Keyword(s):  
High Performance ◽  
Laser System ◽  
Level Laser

scholarly journals Spectroscopy Methods and Applications of the Tor Vergata Laser-Plasma Facility Driven by GW-Level Laser System

2011 ◽  
Vol 2011 ◽  
pp. 1-28 ◽  
Author(s):  
M. Francucci ◽  
P. Gaudio ◽  
S. Martellucci ◽  
M. Richetta
Keyword(s):  
Laser Plasma ◽  
Laser System ◽  
Line Emission ◽  
Pulsed Laser ◽  
Plasma Source ◽  
Laser Source ◽  
Solid Target ◽  
Glass Laser ◽  
X Ray ◽  
Level Laser

A review focused on plasma induced on solid target by GW-level pulsed laser source is presented. A description of the Tor Vergata laser-plasma source (TVLPS), at the Tor Vergata University in Rome, is given. Such a facility uses a 1  GW, tabletop, multistage Nd:YAG/Glass laser system, delivering infrared (IR) pulses with nanosecond width and 1064 nm wavelength (TEM00 mode). Its applications are discussed providing: wide analysis of IR → soft X-ray conversion efficiency (1.3–1.55 keV); measures and modeling of line emission in soft X-ray spectra, such as those from zinc plasma near Ne-like Zn XXI and from barium plasma near Ni-like Ba XXIX. Particular attention is devoted to high-n dielectronic Rydberg satellites for finding a useful diagnostic tool for plasma conditions. Dependence of plasma spectra on laser parameters is shown. Finally, microradiography applications are presented for thin biological samples. Images permit to visualize specific structures and detect bioaccumulation sites due to contamination from pollutants.

Electron acceleration at ELI-Beamlines: Towards high-energy and high-repetition rate accelerators

2019 ◽  
Vol 34 (34) ◽  
pp. 1943010
Author(s):  
C. M. Lazzarini ◽  
L. V. Goncalves ◽  
G. M. Grittani ◽  
S. Lorenz ◽  
M. Nevrkla ◽  
...  
Keyword(s):  
Laser System ◽  
Critical Density ◽  
Laser Pulses ◽  
High Energy ◽  
High Repetition Rate ◽  
Beam Parameter ◽  
Laser Wakefield Acceleration ◽  
Laser Guiding ◽  
Electron Beam Parameter ◽  
Level Laser

The high energy electron experimental platform * at ELI-Beamlines will give to the users high energy tunable electron beams with low energy spread and divergence, by employing laser-wakefield-acceleration scheme (LWFA) driven by PW-class laser system working at 10 Hz. The platform will offer great flexibility over electron beam parameter space and is foreseen to exploit different targets, acceleration and laser-guiding advanced schemes. In this paper we summarize about more compact accelerators that can be envisioned by the use of really short (near single-cycle) fem-mJ-level laser pulses interacting with nanoparticle and solid targets, as well as with specific near-critical density targets. * Originally developed as H.E.L.L., within the Particle acceleration by Laser program (RP3).

Aberration-free broadband stretcher-compressor system for femtosecond petawatt-level laser system based on parametric amplification

2014 ◽  
Vol 27 (6) ◽  
pp. 573-581 ◽  
Author(s):  
V. E. Leshchenko ◽  
V. I. Trunov ◽  
E. V. Pestryakov ◽  
S. A. Frolov
Keyword(s):  
Laser System ◽  
Parametric Amplification ◽  
Level Laser

Instabilities and Tracking of Travelling Wave Patterns in a Three-Level Laser

1998 ◽  
Vol 08 (09) ◽  
pp. 1769-1775 ◽  
Author(s):  
Weiping Lu ◽  
Dejin Yu ◽  
Robert G. Harrison
Keyword(s):  
Laser System ◽  
Theoretical Work ◽  
Travelling Wave ◽  
Travelling Wave Solutions ◽  
Periodic Patterns ◽  
Feedback Form ◽  
Wave Solutions ◽  
Level Laser ◽  
Spatially Extended ◽  
Local Feedback

Based on our earlier theoretical work on tracking periodic patterns into spatiotemporal chaotic regimes in spatially extended systems, we present in this article a case study of a high-aspect-ratio three-level laser. Following a detailed investigation into travelling wave solutions of the laser system and their stability conditions, we discuss ways of stabilising these solutions by local feedback algorithms. In numerical simulations, we choose Pyragus continuous delayed feedback algorithm to be the local feedback form and demonstrate that stable travelling wave solutions of the spatially extended three-level laser can be greatly extended to unstable regions in the presence of this feedback

scholarly journals Bright High-Order Harmonic Generation around 30 nm Using Hundred-Terawatt-Level Laser System for Seeding Full Coherent XFEL

2018 ◽  
Vol 8 (9) ◽  
pp. 1446 ◽  
Author(s):  
Luyao Zhang ◽  
Yinghui Zheng ◽  
Guicun Li ◽  
Zhengmao Jia ◽  
Yanyan Li ◽  
...  
Keyword(s):  
Harmonic Generation ◽  
Beam Quality ◽  
Laser System ◽  
High Harmonic ◽  
High Order ◽  
Laser Source ◽  
High Order Harmonic Generation ◽  
X Ray ◽  
High Order Harmonic ◽  
Level Laser

In the past few years, the laser wakefield acceleration (LWFA) electron is a hot topic. One of its applications is to produce soft X-ray free-electron laser (XFEL). During this process, high harmonic generation (HHG) is a potential seed. To decrease the timing jitter between LWFA and HHG, it is better for them to come from the same laser source. We have experimentally investigated bright high-order harmonic generation with a 200-terawatt (TW)/1-Hz Ti: Sapphire laser system. By using the loosely focused method and optimizing the phase-matching conditions, we have obtained bright high-order harmonics around 30 nm. Output energy of the 29th harmonic (27.6 nm) reaches as high as 100 nJ per pulse, and the harmonic beam divergence is estimated to be 0.3 mrad in a full width at half maximum (FWHM). Although the hundred-TW-level laser system has the problems of poor beam quality and shot-to-shot energy fluctuation for HHG, the generated soft X-ray (~30 nm) sources can also have good stability by carefully optimizing the laser system.

scholarly journals First Experience in Small Incision Lenticule Extraction with the Femto LDV Z8 and Lenticule Evaluation Using Scanning Electron Microscopy

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Mengmeng Wang ◽  
Fengju Zhang ◽  
Christine Carole Copruz ◽  
Longhui Han
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peak Pressure ◽  
Laser System ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Level Laser ◽  
Lenticule Extraction ◽  
Time Parameters ◽  
Scanning Electron

Purpose. To evaluate the specifications and technique properties of the new Femto LDV Z8 in creating intrastromal refractive lenticules during small incision lenticule extraction (SMILE). Methods. Six enucleated porcine eyeballs were equally divided into two groups (Femto LDV Z8 or VisuMax) and were randomly assigned to three experienced refractive surgeons who performed SMILE on each group. Five intraoperative time parameters and surgeons’ satisfaction on the surgical procedure were compared between two groups. Postoperatively, the roughness of the lenticule surfaces and the irregularity of edges were observed by scanning electron microscopy (SEM) and were also compared between the two groups. Results. Longer time on suction peak pressure, total laser application, and total surgery were spent in the Femto LDV Z8 group as compared with the VisuMax group. The Femto LDV Z8 group applied OCT scanning and offsetting before performing the laser procedure, which expended more time for these crucial steps. The widest range of surgeons’ satisfaction scores was found in the step of lenticule interface identification of the Femto LDV Z8 group. The roughness scores of the anterior and posterior lenticule surfaces were statistically less in the Femto LDV Z8 group than in the VisuMax group (anterior, ×180, p=0.039; anterior, ×250, p=0.337; posterior, ×180, p=0.006; and posterior, ×250, p=0.007). Conclusions. Femto LDV Z8 showed promising performances as a novel SMILE equipment for the correction of myopia. It has special and unique features for SMILE procedures, which need more learning and researching processes. With its low-energy high-frequency nJ-level laser system, the Femto LDV Z8 provided smoother lenticule surface than VisuMax.

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