Signal build-up from noise and seeding in plasma-based x-ray lasers

Using the x-ray lasers as amplifiers of ultrashort x-ray pulses has been investigated as a scheme for ultimate light sources. For successful implementation, the characteristics of the scheme should be taken into account in designing the amplifiers. In this paper, the basic physics and characteristics of the scheme were analyzed by using the Maxwell-Bloch equations incorporating time-dependent gain, random spontaneous emission, atomic level degeneracy, and radiation polarization. The variation of the pulse parameters such as energy, bandwidth, pulsewidth, and polarization were explained based on a simple mechanism of pulse growth and also compared to that in the conventional x-ray lasers. These results should be the basic information for a practical implementation of the scheme.

[1]  Yong Wang,et al.  Phase-coherent, injection-seeded, table-top soft-X-ray lasers at 18.9 nm and 13.9 nm , 2008 .

[2]  Tae Jun Yu,et al.  Demonstration of a saturated Ni-like Ag x-ray laser pumped by a single profiled laser pulse from a 10-Hz Ti:sapphire laser system , 2008 .

[3]  Karol A. Janulewicz,et al.  Amplification of a high-order harmonic pulse in an active medium of a plasma-based x-ray laser , 2009 .

[4]  Felix Staub,et al.  Gain Saturation of the Ni-like Antimony Laser at 11.4 nm in Grazing-Incidence Pumping Geometry , 2009 .

[5]  Paul Gibbon,et al.  High-order harmonics from laser-irradiated plasma surfaces , 2009 .

[6]  F. Krausz,et al.  Intense few-cycle laser fields: Frontiers of nonlinear optics , 2000 .

[7]  Karol A. Janulewicz,et al.  Pulse buildup from noise and intrinsic polarization of plasma-based x-ray lasers , 2011 .

[8]  F. Krausz.  Attosecond Physics , 2007, 2007 Conference on Lasers and Electro-Optics - Pacific Rim.

[9]  Zenghu Chang,et al.  Pulse duration measurements of grazing-incidence-pumped high repetition rate Ni-like Ag and Cd transient soft x-ray lasers. , 2006, Optics letters.

[10]  G. Jamelot,et al.  Experimental study of the temporal coherence and spectral profile of the 13.9 nm transient X-ray laser , 2006 .

[11]  Chul Min Kim,et al.  Coherent amplification of an ultrashort pulse in a high- and swept-gain medium with level degeneracy. , 2010, Physical review letters.

[12]  S. V. Bulanov,et al.  Optics in the relativistic regime , 2006 .

[13]  Eric Esarey,et al.  Physics of laser-driven plasma-based electron accelerators , 2009 .

[14]  G. Tallents.  TOPICAL REVIEW: The physics of soft x-ray lasers pumped by electron collisions in laser plasmas , 2003 .

[15]  T. Mocek,et al.  A high-intensity highly coherent soft X-ray femtosecond laser seeded by a high harmonic beam , 2004, Nature.