| 摘要 |
<p>A method and apparatus for providing a laser beam that is automatically aligned with a substantially rigid, stabilized platform or frame that can be oriented over a wide angular range, such as by the gimbals of a laser pointing and tracking system. A single-transverse-mode master laser oscillator (12) is mounted on the stabilized platform (13) which is part of the inner gimbal, which can be rotated about an elevation axis (16), and a multipass laser amplifier (21) with a phase conjugation mirror (22) and an optional nonlinear frequency-conversion device (20) are located off the inner gimbal. An outer gimbal or pedestal mount permits rotation about an azimuthal axis (17). The laser oscillator (12) and laser amplifier (21) are coupled by means of a beamsplitter (15) and two reflecting elements (18 and 19). The laser media used for the oscillator (12) and amplifier (21) are either the same, or compatible media having the same wavelength. In an alternative embodiment the two reflecting elements are replaced by a flexible light waveguide such as a glass fiber. The phase conjugation mirror (22) compensates the beam for the effects of optical aberrations caused by thermally induced changes in the amplifier medium and the nonlinear medium (if used) and also compensates the beam for angular tilt and jitter in the beam line of sight due to structural flexibility and motion of the stabilized platform. Four different embodiments are described in which the phase conjugation mirror is based on stimulated Brillouin scattering, degenerate four-wave mixing, three-wave mixing, and photon echo effects, respectively.</p> |
