| 摘要 |
<p>An active laser is slaved in an offset frequency relationship to an ultrastable reference laser, by a comparator with a substantially infinite capture range in order to preclude phase-locking on a harmonic or mirror image of the desired offset frequency. The frequency of such a slaved laser is then virtually immune to retro-reflection of its own light back into its resonant cavity, and gains a frequency stability equal to that of the reference. Further, the reference laser is preferably stabilizer against retro-reflection of its own light by a method involving selective displacement of objects in the path of the reference laser beam, detection of a Doppler-shifted retro-reflected radiation, and insertion of appropriate optical controls in the beam path to eliminate such retro-reflected radiation from impinging on the reference laser cavity. Multiple laser systems are disclosed in which the active lasers are both series referenced and parallel referenced to a reference laser.</p> |
