the context of representative embodiments that are not intended to be limiting in any way i e the following description of representative embodiments is not intended to limit the scope of the invention to the specifically described embodiments but rather to enable any person skilled in the art to make and use the invention as will be recognized by any person skilled in the relevant art modifications and changes can be made to the described embodiments without departing from the scope of the invention as defined in the appended claims laser amplification can be achieved using a u201c direct drive u201d scheme as shown in fig1 a laser pulse l propagating from the left in the figure enters the lumen of a reflective e g metallic liner having length u03bb over which a large electric current is discharged thereby imploding the liner in a z pinch manner as the laser beam propagates through the liner it reflects back and forth from and between the mutually approaching walls of the imploding liner which causes the frequency of the beam to rise steadily with the number of photons in the liner being conserved the energy of the laser beam is amplified by its conversion to shorter wavelengths because the liner behaves as a waveguide for electromagnetic waves it exhibits a cut off frequency u03bd c u02dc c r where c is the velocity of light and r is the inner radius of the liner consequently typically no laser pulse having a frequency less than u03bd c propagates through the liner landau and lifshitz electrodynamics of continuous media pergamon press new.