Powerlase Limited

University of California

Powerless Limited

Ian P Mercer

David Rupert Klug

Daniel A Allwood

Jason Palmer

Alan G Taylor

Stephen Anthony Payne

Raymond John Beach

Michael Dale Perry

Eric C Honea

Christopher J Barnett

A high energy photon source for generating EUV radiation comprises a nozzle emitting a supersonic stream of source material, a laser or electrical/magnetic pre-ionization mechanism and a laser or electrical/magnetic excitation mechanism and a skimmer plate between them providing a collimated high density beam of source material for excitation.

High flux, high energy photon source

In a solid state, optically end-pumped laser, the laser gain medium has a tapered diameter to minimize the maximum path length of barrelling amplified stimulated emission (ASE), and a roughened surface region at one end to scatter barrelling ASE out of the gain medium; thereby minimizing the negative effective of barrelling ASE's, and inhibiting the trapping of rays with a large longitudinal component, but disallowing a cyclic, i.e. repeated, pass path with specular reflections.

Laser apparatus

A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.

Pulse laser resonator

An extreme ultraviolet radiation generator is disclosed in which Xenon gas is continuously ejected from a high pressure nozzle into a low pressure chamber to generate Xenon atom clusters which are irradiated with a high repetition rate pulsed laser to form a plasma and yield quasi-continuous EUV generation. The nozzle has a beveled outer rim to enable the focus point of the laser light to be brought close to the nozzle. The nozzle is cooled to a temperature at which background Xenon gas condenses onto the nozzle forming a protective layer. A gas compressor serves to recirculate the Xenon gas and batch purification triggered by a mass spectrometer monitoring gas purity may be periodically applied.

Electromagnetic radiation generation using a laser produced plasma

By tapering the diameter of a flanged barrel laser rod over its length, the maximum trapped path length of a barrel mode can be dramatically reduced, thereby reducing the ability of the trapped spontaneous emission to negatively impact laser performance through amplified spontaneous emission (ASE). Laser rods with polished barrels and flanged end caps have found increasing application in diode array end-pumped laser systems. The polished barrel of the rod serves to confine diode array pump light within the rod. In systems utilizing an end-pumping geometry and such polished barrel laser rods, the pump light that is introduced into one or both ends of the laser rod, is ducted down the length of the rod via the total internal reflections (TIRs) that occur when the light strikes the rod's barrel. A disadvantage of using polished barrel laser rods is that such rods are very susceptible to barrel mode paths that can trap spontaneous emission over long path lengths. This trapped spontaneous emission can then be amplified through stimulated emission resulting in a situation where the stored energy available to the desired lasing mode is effectively depleted, which then negatively impacts the laser's performance, a result that is effectively reduced by introducing a taper onto the laser rod.

Growing community of inventors

Keymer, United Kingdom

Ian P Mercer