A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions
of some of the scientists and engineers involved, especially those that happen to have South African connections.
Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These
applications involved atmospheric physicists, several astronauts and many of the staff recruited into the Soviet and North
American lunar exploration programmes. There is a strong interest in South Africa in both LIDAR and lunar ranging.
Shortly after the birth of the laser (and even just prior) theoretical work on photonic propulsion and space propulsion by
laser ablation was initiated by Georgii Marx, Arthur Kantrowitz and Eugen Saenger. Present or near future experimental
programs are developing in the following fields: laser ablation propulsion, possibly coupled with rail gun or gas gun
propulsion; interplanetary laser transmission; laser altimetry; gravity wave detection by space based Michelson
interferometry; the de-orbiting of space debris by high power lasers; atom laser interferometry in space. Far future
applications of laser-photonic space-propulsion were also pioneered by Carl Sagan and Robert Forward. They envisaged
means of putting Saenger's ideas into practice. Forward also invented a laser based method for manufacturing solid antimatter
or SANTIM, well before the ongoing experiments at CERN with anti-hydrogen production and laser-trapping.
SANTIM would be an ideal propellant for interstellar missions if it could be manufactured in sufficient quantities. It
would be equally useful as a power source for the transmission of information over light year distances. We briefly
mention military lasers. Last but not least, we address naturally occurring lasers in space and pose the question: "did the
Big Bang lase?"
Non-solid and non-rigid optics employ gas and liquid transmission and reflection, as well as flexible membranes
to influence laser beams, laser driven particle beams and harmonic generators. Some examples are acoustic
gratings, phase conjugate mirrors, Raman cells, gas-jets, gas and flame lenses, gas capillaries, plasma cones,
mercury mirrors and rotating and aerodynamic windows. Industrial scale laser propulsion, laser fusion, laser
accelerators, lithography and laser isotope separation will necessitate handling average beam powers very different
from present day single shot demonstrations. Standard solid state optics may prove incapable of handling such
Active galactic nuclei, supernovae and some massive luminous stars are sources of intense radiation at all wavelengths. η Carinae is an unusual radiation source producing UV laser-like radiation. Estimates of the intensity of these sources indicate that interstellar dust clouds produced during the star's penultimate period of stability, will be strongly affected, with the possibility of some dust particles being accelerated to near relativistic velocities. Theoretical work by Bingham, Marx, McInnes, Spitzer, Tsytovich is reviewed and its applicability to photon propulsion is discussed. Photon propulsion will be the ideal propellant for nanoscale satellites.
We report on simulations of atomic cluster explosions upon interaction with high-intensity femtosecond laser pulses. By using a 2D and 3D fully relativistic PIC code we investigate the dynamics of hydrogen and argon cluster explosions providing information about the time-resolved ion energy spectra, for different laser intensities. Multi-cluster systems are also studied and the influence of cluster distribution in ionic energy spectra is shown. Results indicate that MeV ions are produced through Coulomb explosion of the atomic clusters and the possibility of capturing most of these ions with a specially designed magnetic focusing system is discussed.
Conference Committee Involvement (1)
Harnessing Relativistic Plasma Waves as Novel Radiation Sources from Terahertz to X-rays and Beyond