| 摘要 |
A light guide (30) is placed at the focus of a collimator lens (31). The resulting parallel beam of light (22) enters a beam splitter assembly (20), with three parallel mirrors set at an angle of 45 degrees to the beam of light. The central, partially reflecting, mirror (20') is in the way of the collimated beam. It may let half of the light through (23) and may reflect half of it to a first totally reflecting mirror (25), which produces a beam (24) parallel to the transmitted beam. The two beams pass through a diffraction grating (29), which produces diffracted beams. The two zero order beams are reflected and reversed at a reflector (21), e.g. a corner cube, so that the first beam travels back along the path of the second and vice-versa. The beam splitter sends part of the reflected light back to the collimator lens and part of it (27) escapes from the system and forms the output of the laser. |
