Coherent bremsstrahlung generation of harmonics in a laser-produced plasma
Journal Article
·
· Quantum Electronics (Woodbury, N.Y.)
- P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)
Foundations of a theory of generation of the harmonics of a laser pump in a fully ionised plasma are proposed. This theory makes it possible to describe the relationships governing harmonic generation in an analytical form. For an elliptically polarised pump field with a low degree of circular polarisation A, the range of plasma parameters is established in which the number of harmonics is found to be of the order of A{sup -1}. Anomalous polarisation properties of the harmonics are predicted. In this case, their polarisation is seen to be nearly perpendicular to the pump polarisation and the degree of circular polarisation increases with the harmonic order number. The harmonic-order-dependent intensity of the pump field which results in circular polarisation of a harmonic is determined making allowance for thermal plasma motion. The conditions under which increasing the low degree of circular pump polarisation increases the efficiency of harmonic generation are established. The nonlinear dependence of the pump polarisation on its intensity under the conditions of collisional absorption in a plasma are identified and an instability of the circular polarisation is revealed. For a plane-polarised pump, it is shown how the maximum power of a harmonic and the pump power corresponding to this maximum scale up with the harmonic order number. The conditions under which the number of harmonics generated is limited owing to the relativistic nature of electron motion in the pump field are established. This effect appears for an unexpectedly weak relativity. (invited paper)
- OSTI ID:
- 21437814
- Journal Information:
- Quantum Electronics (Woodbury, N.Y.), Journal Name: Quantum Electronics (Woodbury, N.Y.) Journal Issue: 1 Vol. 29; ISSN 1063-7818
- Country of Publication:
- United States
- Language:
- English
Similar Records
On the bifurcation of the circular polarisation of the fifth and seventh pump-field harmonics generated in the plasma produced by the ionisation of a gas of excited hydrogen-like atoms
Polarisation of the third harmonic generated by the pump field caused by collisions of electrons and ions in a plasma produced upon ionisation of a gas of excited hydrogen-like atoms
Polarisation dependences of harmonic generation in the plasma produced in the ionisation of excited-state hydrogen-like atoms
Journal Article
·
Wed May 31 00:00:00 EDT 2006
· Quantum Electronics (Woodbury, N.Y.)
·
OSTI ID:21456893
Polarisation of the third harmonic generated by the pump field caused by collisions of electrons and ions in a plasma produced upon ionisation of a gas of excited hydrogen-like atoms
Journal Article
·
Thu Jun 30 00:00:00 EDT 2005
· Quantum Electronics (Woodbury, N.Y.)
·
OSTI ID:21470769
Polarisation dependences of harmonic generation in the plasma produced in the ionisation of excited-state hydrogen-like atoms
Journal Article
·
Sun Feb 27 23:00:00 EST 2005
· Quantum Electronics (Woodbury, N.Y.)
·
OSTI ID:21470696