| 摘要 |
A lens system for use with elliptical optical sources includes a spherical fiber lens disposed beyond a conventional confocal lens arrangement. The spherical fiber lens is disposed in the optical path at the point where the slow axis (X ray) crosses the fast axis (Y ray); the rays will be "circular" and will thereafter propagate as a circular wavefront. The coupling efficiency of such a system is thus improved from approximately 40% to over 80%. The radius of the spherical endface of the fiber lens may be adjusted to improve the coupling efficiency. The spherical fiber lens is easily formed by fusing a section of "coreless" silica fiber onto the endface of a conventional single mode fiber. The end of the silica fiber is thereafter prepared (by heating, etching, polishing, or laser machining, for example) to provide a spherical endface with the desired radius.
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