scholarly journals Improved beam waist formula for ultrashort, tightly focused linearly, radially, and azimuthally polarized laser pulses in free space

2014 ◽  
Vol 39 (5) ◽  
pp. 1258 ◽  
Author(s):  
Liang Jie Wong ◽  
Franz X. Kärtner ◽  
Steven G. Johnson
Keyword(s):  
Free Space ◽  
Laser Pulses ◽  
Beam Waist

LASER-INDUCED MULTIPHOTON PHOTOCONDUCTIVITY IN DIRECT AND INDIRECT BAND GAP CRYSTALS USING Z-SCAN TECHNIQUE

2009 ◽  
Vol 23 (23) ◽  
pp. 2783-2789 ◽  
Author(s):  
ARUN GAUR ◽  
D. K. SHARMA ◽  
K. S. SINGH ◽  
NAGESHWAR SINGH
Keyword(s):  
Absorption Coefficient ◽  
Band Gap ◽  
Laser Pulses ◽  
Beam Waist ◽  
Photon Absorption ◽  
Nanosecond Laser ◽  
Direct Band Gap ◽  
Direct Band ◽  
Nanosecond Laser Pulses ◽  
Indirect Band Gap

Nanosecond laser pulses have employed the photoconductive Z-scan technique. Photoconductivity traces measured by moving the sample across the laser beam waist were used for measuring two and three-photon absorption processes. The value of the three-photon absorption coefficient β3=9.6×10-10 cm 3/ GW 2 in the case of direct, and 8.96×10-12 cm 3/ GW 2 and 5.0×10-12 cm 3/ GW 2 in the case of indirect band gap crystals have been estimated from a comparison of traces measured by exciting the sample with the first and second harmonics of Nd : YAG laser. The low value of β3 in the case of indirect band gap crystals compared to direct band gap crystals is attributed to phonon-assisted transitions.

scholarly journals Linear-Field Particle Acceleration in Free Space by Spatiotemporally Structured Laser Pulses

2018 ◽  
Author(s):  
Liang Jie Wong ◽  
Kyung-Han Hong ◽  
Sergio Carbajo ◽  
Arya Fallahi ◽  
Philippe Piot ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Free Space ◽  
Laser Pulses ◽  
Linear Field

Heterogeneous Nucleation of Spatially Coherent Damage Structures in Crystalline Silicon with Picosedcond 1.06 μm and 0.53 μm Laser Pulses

1980 ◽  
Vol 1 ◽  
Author(s):  
R.M. Walser ◽  
M.F. Becker ◽  
J.G. Ambrose ◽  
D.Y. Sheng
Keyword(s):  
Electric Field ◽  
Heterogeneous Nucleation ◽  
Crystallographic Orientation ◽  
Free Space ◽  
Crystalline Silicon ◽  
Laser Pulses ◽  
Laser Wavelength ◽  
Beam Spot ◽  
Polarized Beams ◽  
Linearly Polarized

Several types of periodic ripple structures have been observed on the surface of solids that have been laser irradiated with beam intensities near their melting thresholds.1-7 We restrict our attention here to the coherent, onedimensional (RD) gratings induced by linearly polarized beams.3-7 These gratings have a period close to the free space laser wavelength (λ0) for normally incident beams and are normally found in the beam spot near the melt boundary (Fig. 1). The grating lines are always perpendicular to the optical electric field Ei independent of the crystallographic orientation of the sample.

Interference of phase-shifted chirped laser pulses for secure free-space optical communications

2018 ◽  
Vol 57 (10) ◽  
pp. C98 ◽  
Author(s):  
G. S. Rogozhnikov ◽  
V. V. Romanov ◽  
N. N. Rukavishnikov ◽  
V. Ya. Molchanov ◽  
K. B. Yushkov
Keyword(s):  
Optical Communications ◽  
Free Space ◽  
Laser Pulses ◽  
Free Space Optical

scholarly journals Gain dynamics of a free-space nitrogen laser pumped by circularly polarized femtosecond laser pulses

2014 ◽  
Vol 22 (16) ◽  
pp. 19005 ◽  
Author(s):  
Jinping Yao ◽  
Hongqiang Xie ◽  
Bin Zeng ◽  
Wei Chu ◽  
Guihua Li ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Free Space ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Nitrogen Laser ◽  
Circularly Polarized

scholarly journals Diagnostics of peak laser intensity based on the measurement of energy of electrons emitted from laser focal region

2015 ◽  
Vol 33 (3) ◽  
pp. 361-366 ◽  
Author(s):  
M. Kalashnikov ◽  
A. Andreev ◽  
K. Ivanov ◽  
A. Galkin ◽  
V. Korobkin ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Laser Pulses ◽  
Maximum Energy ◽  
Beam Waist ◽  
Focal Region ◽  
Low Density ◽  
Particle In Cell ◽  
Peak Intensity ◽  
Low Density Plasma ◽  
Density Plasma

AbstractA new method to determine the peak intensity of focused relativistic laser pulses is experimentally justified. It is based on the measurement of spectra of electrons, accelerated in the beam waist. The detected electrons were emitted from the plasma, generated by nonlinear ionization of low-density gases (helium, argon, and krypton) in the focal area of a laser beam with the peak intensity >1020 W/cm2. The measurements revealed generation of particles with the maximum energy of a few MeV, observed at a small angle relative to the beam axis. The results are supported by numerical particle-in-cell simulations of a laser–low-density plasma interaction. The peak intensity in the focal region derived from experimental data reaches the value of 2.5 × 1020 W/cm2.

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