Intense THz-radiation generation from an intracavity saturable Bragg reflector in a magnetic field

1998 ◽  
Author(s):  
H. Ohtake ◽  
Zhenlin Liu ◽  
S. Izumida ◽  
N. Sarukura ◽  
Y. Segawa ◽  
...  
1998 ◽  
Vol 37 (Part 2, No. 2A) ◽  
pp. L125-L126 ◽  
Author(s):  
Nobuhiko Sarukura ◽  
Hideyuki Ohtake ◽  
Zhenlin Liu ◽  
Taro Itatani ◽  
Takeyoshi Sugaya ◽  
...  

2016 ◽  
Vol 34 (2) ◽  
pp. 378-383 ◽  
Author(s):  
N.K. Verma ◽  
P. Jha

AbstractA one-dimensional (1D) numerical model for studying enhanced terahertz (THz) radiation generation by mixing of ordinary and extraordinary modes of two-color laser pulses propagating in magnetized plasma has been presented. The direction of the static external magnetic field is such that one of the two laser pulses propagates in the extraordinary mode, while the other pulse propagates in the ordinary mode, through homogeneous plasma. A transverse electromagnetic wave with frequency in the THz range is generated due to the presence of the external magnetic field. It is observed that larger amplitude THz radiation can be generated by mixing of the ordinary and extraordinary modes of the two-color laser pulses as compared with the single laser pulse propagating in the extraordinary mode. Further, 2D simulations using the XOOPIC code show that the fields obtained via simulation study are compatible with those obtained from the numerical model.


1999 ◽  
Vol 38 (Part 2, No. 11B) ◽  
pp. L1333-L1335 ◽  
Author(s):  
Tze-An Liu ◽  
Kai-Fung Huang ◽  
Ci-Ling Pan ◽  
Zhenlin Liu ◽  
Shingo Ono ◽  
...  

2016 ◽  
Vol 34 (4) ◽  
pp. 569-575 ◽  
Author(s):  
A. Hematizadeh ◽  
S.M. Jazayeri ◽  
B. Ghafary

AbstractThis paper presents analytical calculations for terahertz (THz) radiation by beating of two cosh-Gaussian laser beams in a density rippled collisional magnetized plasma. Lasers beams exert a ponderomotive force on the electrons of plasma in beating frequency which generates THz waves. The magnetic field was considered parallel to the direction of lasers which leads to propagate right-hand circularly polarized or left-hand circularly polarized waves in the plasma depending on the phase matching conditions. Effects of collision frequency, decentered parameter of lasers and the magnetic field strength are analyzed for THz radiation generation. By the optimization of laser and plasma parameters, the efficiency of order 27% can be achieved.


2019 ◽  
Vol 37 (4) ◽  
pp. 415-427
Author(s):  
Gunjan Purohit ◽  
Vinod Rawat ◽  
Priyanka Rawat

AbstractAn analytical and numerical study has been carried out for the generation of terahertz (THz) radiation by beating of two intense cosh-Gaussian laser beams (decentered Gaussian beams) in the rippled density magnetized plasma under the relativistic–ponderomotive regime. In this process, both laser beams exert a relativistic–ponderomotive force on plasma electrons at the beat frequency and impart them an oscillatory velocity in the presence of a static magnetic field. Due to coupling between this nonlinear oscillatory velocity with density ripple, nonlinear current is generated that excites the THz radiation at the different frequency. Higher-order paraxial-ray approximation (non-paraxial theory) has been used in this study. The effects of the decentered parameter, magnetic field, and density ripple on the THz radiation generation in ripple density magnetized plasma have been investigated. Further, the effect of beating of laser beams on the THz field amplitude and the efficiency of THz radiation have been studied. The amplitude and efficiency of the emitted radiation are found to be highly sensitive to the decentered parameter, magnetic field, and density ripple. It has been found that the amplitude and efficiency of the generated THz radiation increase significantly with increasing the values of decentered parameter, magnetic field, and density ripple.


2013 ◽  
Vol 31 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Prateek Varshney ◽  
Vivek Sajal ◽  
K.P. Singh ◽  
Ravindra Kumar ◽  
Navneet K. Sharma

AbstractA scheme of terahertz radiation generation is proposed by beating of two extra-ordinary lasers having frequencies and wave numbers$\lpar {\rm \omega}_1\comma \; \vec k_1 \rpar $and$\lpar {\rm \omega}_2\comma \; \vec k_2 \rpar $, respectively in a magnetized plasma. Terahertz wave is resonantly excited at frequency$\lpar {\rm \omega}_1 - {\rm \omega}_2 \rpar $and wave number (k1 − k2 + q) with a wave number mismatch factorqwhich is introduced by the periodicity of plasma density ripples. In this process, the lasers exert a beat ponderomotive force on plasma electrons and impart them an oscillatory velocity with both transverse and longitudinal components in the presence of transverse static magnetic field. The oscillatory velocity couples with density ripples and produces a nonlinear current that resonantly excites the terahertz radiation. Effects of periodicity of density ripples and applied magnetic field are analyzed for strong THz radiation generation. The terahertz radiation generation efficiency is found to be directly proportional to the square of density ripple amplitude and rises with the magnetic field strength. With the optimization of these parameters, the efficiency ~10−3is achieved in the present scheme. The frequency and power of generated THz radiation can be better tuned with the help of parameters like density ripple amplitude, periodicity and applied magnetic field strength in the present scheme.


2014 ◽  
Vol 33 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Prateek Varshney ◽  
Vivek Sajal ◽  
Sweta Baliyan ◽  
Navneet K. Sharma ◽  
Prashant K. Chauhan ◽  
...  

AbstractResonant THz radiation generation is proposed by beating of two spatial-triangular laser pulses of different frequencies (ω1, ω2) and wave numbers $\lpar \vec k_1 \comma \; \vec k_2 \rpar $ in plasma having external static magnetic field. Laser pulses co-propagating perpendicular to a dc magnetic field exert a nonlinear ponderomotive force on plasma electrons, imparting them an oscillatory velocity with finite transverse and longitudinal components. Oscillatory plasma electrons couple with periodic density ripples n′ = nq0eiqz to produce a nonlinear current, i.e., responsible for resonantly driving terahertz radiation at $\lpar {\rm \omega} = {\rm \omega} _1 - {\rm \omega} _2 \comma \; \vec k = \vec k_1 - \vec k_2 + \vec q\rpar $. Effects of THz wave frequency, laser beam width, density ripples, and applied magnetic field are studied for the efficient THz radiation generation. The frequency and amplitude of THz radiation were observed to be better tuned by varying dc magnetic field strength and parameters of density ripples (amplitude and periodicity). An efficiency about 0.02 is achieved for laser intensity of 2 × 1015 W/cm2 in a plasma having density ripples about 30%, plasma frequency about 1 THz and magnetic field about 100 kG.


2015 ◽  
Vol 33 (3) ◽  
pp. 519-524 ◽  
Author(s):  
Anil K. Malik ◽  
Kunwar Pal Singh

AbstractWe propose a mechanism of highly focused, tunable and high-intensity terahertz (THz) radiation generation by frequency-mixing of two super-Gaussian lasers with frequencies ω1, ω2 and wave numbers k1, k2 (laser profile index p > 2) in a corrugated plasma in the presence of external static magnetic field ${B_0}\hat z$. In this process, a strong nonlinear ponderomotive force is offered to the plasma electrons at frequency ω′ = ω1 − ω2 and wave number k′ = k1 − k2 by laser beams. The ponderomotive force results in a strong, controllable nonlinear transverse oscillatory current, which can be optimized by optimizing the external magnetic field, ripple parameters, and laser indexes. This controllable current produces focused and intense THz radiation of tunable frequency and power along with a remarkable efficiency ~25%.


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