Beam delivery system for molecular fluorine (F2) laser
AssigneeLambda Physik AG
InventorSergei V. Govorkov
Life of this patent
Estimating the term…
Abstract
A method and apparatus are provided for delivering a laser beam from a laser, such as an F2 laser, to a target through a sealed enclosure. The enclosure is evacuated and back-filled with an inert gas repeatedly for a number of times sufficient to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter, an inert gas flow is established and maintained within the enclosure during operation of the laser. Propagation with significant transmittance of a sub-200 nm beam through the enclosure is particularly enabled.
Claims44
A laser system for delivering a laser beam to a workpiece, comprising:
- a discharge chamber filled with a gas mixture;
- a pair of electrodes coupled with a power supply circuit for producing a pulsed discharge to energize the molecular fluorine;
- a resonator surrounding the discharge chamber for generating a laser beam;
- and
- an enclosure sealing at least a portion of the beam path exiting the laser from the outer atmosphere and having an evacuation port for connecting to a pump which reduces the pressure in the enclosure and removes photoabsorbing gaseous species from the enclosure for evacuating the enclosure and an inlet port and an outlet port for flowing an inert gas within said enclosure after evacuating said enclosure to enable the laser beam to propagate along said beam path, such that the energy of the beam can reach the workpiece without substantial attenuation due to the presence of photoabsorbing species along said beam path.
A beam delivery system for connecting to a laser for delivering a laser beam to a workpiece, comprising:
- an enclosure sealing at least a portion of the beam path exiting the laser from the outer atmosphere;
- an evacuation port valve-connected to the enclosure and connected to a pump which reduces the pressure in the enclosure and removes photoabsorbing gaseous species from the enclosure for selectively evacuating the enclosure;
- an inlet port connected to an inert gas supply for flowing said inert gas within said enclosure after evacuating said enclosure;
- and
- an outlet port,
- whereby in use, the enclosure is evacuated and backfilled with the inert gas a number of times and thereafter a low level flow of inert gas is established within the enclosure to enhance transmission of laser energy therethrough.
A laser system, comprising:
- a discharge chamber filled with a gas mixture;
- a pair of electrodes coupled with a power supply circuit for producing a pulsed discharge;
- a resonator surrounding the discharge chamber for generating a laser beam;
- means for sealing a beam path of the laser system from the outer atmosphere;
- means for evacuating said beam path;
- and
- means for filling said beam path with an inert gas and flowing said inert gas along said beam path, to enable said laser beam to propagate along said beam path, such that the energy of the beam can reach a workpiece without substantial attenuation due to the presence of photoabsorbing species alone said beam path.
A method of delivering laser light to a target through a sealed enclosure, comprising the steps of:
- evacuating said enclosure;
- filling said enclosure with an inert gas;
- repeating said evacuating and filling steps a predetermined number of times;
- and
- establishing a flow of said inert gas within said enclosure, to reduce absorption of the laser light as it traverses the enclosure.
Dependencies are inferred from the claim text.