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US 5,970,082 AGranted
Very narrow band laser
AssigneeCymer, Inc.
InventorAlexander I. Ershov
Life of this patent
Estimating the term…
Abstract
A very narrow band laser. The very narrow bandwidth is achieved by creating an unstable resonance cavity using a cylindrical, partially-reflecting mirror to provide an output coupler in combination with a line narrowing module having a beam expander and a curved grating.
Claims17
A narrow band laser comprising:
- A. a gain medium,
- B. an unstable resonance cavity comprised of:
- (1) an output coupler comprising a partially reflecting convex cylindrical mirror defining an output coupler curved surface,
- (2) a line narrowing module comprising:
- (a) a beam expander,
- (b) a grating having an adjustable convex curved surface wherein said adjustable curved surface of said grating is adjusted to compensate for wavefront modification caused by said output coupler curved surface.
3 more elements
A very narrow band excimer laser comprising:
- A. a laser chamber containing:
- (1) two elongated electrodes,
- (2) at least one preionizer, and
- (3) a laser gas;
- B. an output coupler comprising a convex cylindrical mirror;
- C. a line-narrowing unit comprising a grating having a cylindrical concave lined surface;
- said grating and said output coupler defining an unstable resonance cavity;
- and
- said lined surface of said grating is curved to compensate for wavefront modification produced by said output coupler.
6 more elements
A very narrow band excimer laser comprising:
- A. a laser chamber containing:
- (1) two elongated electrodes
- (2) at least one preionizer, and
- (3) laser gas comprised of fluorine, a halogen and a buffer gas;
- B. a tunable line narrowing unit comprised of:
- (1) at least one beam expanding prism;
- (2) a tunable concave grating;
- C. an output coupler comprising a convex cylindrical mirror, said tunable grating and said cylindrical mirror defining an unstable resonance cavity wherein said tunable concave grating is tuned to compensate for wavefront modification produced by said output coupler.
5 more elements
Dependencies are inferred from the claim text.