High extraction efficiency cylindrical ring resonator
AssigneeTRW Inc.
InventorJohn D. O'Keefe
Life of this patent
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Abstract
An annular ring resonator for a high-energy laser, including a waxicon/reflaxicon pair and a conical rear mirror, which combine to provide high energy extraction efficiency, reduced sensitivity to alignment errors, and no polarization state mixing. A cylindrical beam returned from a scraper mirror is first expanded by the waxicon to an annular beam that makes a first pass through a gain region of the laser. The annular beam impinges on the conical mirror and is reflected as an annular beam, to make a second pass of the gain region before encountering the reflaxicon, which compacts the beam for transmission to the scraper mirror. One embodiment employs a double-cone rear mirror, and another employs a single conical surface. The structure may also employ feedback decentering.
Claims10
An annular ring resonator for a high-energy laser, having high extraction efficiency, and comprising:
- a conical rear mirror;
- a scraper mmirror;
- a first axicon positioned to receive a generally cylindrical beam from the scraper mirror, and to produce an expanded annular beam to pass through an annular gain region to the conical rear mirror;
- a second axicon, in opposing position to the first axicon, for receiving an annular beam reflected from the conical rear mirror, and producing a generally cylindrical compacted beam for transmission to the scraper mirror, wherein the scraper mirror has an aperture to pass a return beam for transmission to the first axicon;
- and
- optical means for transmitting the compacted beam from the second axicon to the scraper mirror and from the scraper mirror to the first axicon;
- whereby the annular beam makes two passes through the gain region, and the combination of two types of axicons and the conical mirror has substantially no net effect on polarization.
Dependencies are inferred from the claim text.