用光纤准直耦合光路测量大气光学湍流

Fiber microlens collimation and coupling optical path in measuring atmospheric optical turbulence

阐述了利用光纤准直器对组成的耦合光路的附加损耗产生的机理,证明大气湍流运动可引起该光路的附加损耗发生随机变化。根据湍流大气光传播原理,推导出了耦合光功率与光路参数和湍流参数关系式。分析表明:实际湍流大气造成的随机附加损耗主要取决于湍流强度。实验验证了利用该光路可在很短的空气间隙内获得湍流强度的变化信息。

Theory of excess loss in coupling optical path consisting of a pair of fiber optical microlens collimators is presented. It is shown that atmospheric turbulence can result in random variation of the excess loss. According to the light propagation theory in turbulent atmosphere, the relation of coupling light power with optical path and turbulence parameters is derived. It is illuslrated that the random excess loss arisen from actual turbulent atmosphere is dominated by the turbulence intensity. Experiment demonslrates that the turbulence intensity variation information within a short-range air gap can be obtained.