Abstract: The authors designed and realized a laboratory model of an optical intersatellite link employing InGaAs DFB semiconductor lasers operating at a wavelength of $lambda $EQ 1.55 $mu@m. Heterodyne sensing was used for both the spatial acquisition and the spatial tracking processes. An intermediate frequency of IF $EQ 700 MHz was chosen. The definition of wavelength and intermediate frequency asked for the development of a new position detector concept. The function of a quadrant detector was realized by splitting the superimposed beam at the top of a reflecting pyramid into four subbeams. These beams are then detected by separate pin photodiodes. The angular resolution achieved, (without using a telescope) is less than 5 $mu@rad at a detector field of view of 1 mrad. The transmitter laser can be moved within a transverse plane along circular tracks. A microcomputer controls the receiver operation. During the acquisition process spiral scanning of the area of uncertainty is performed. For each search position the local oscillator laser is swept until a beat signal at 700 MHz is detected. Tracking is activated by: first, closing an analog intermediate frequency stabilization loop; second, a digital spatial tracking loop is closed by calculating the required antenna correction from the position sensor information, achieving an average tracking error of $POM 25 $mu@rad.!
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机译：摘要：作者设计并实现了一个采用InGaAs DFB半导体激光器的星际光链路的实验室模型，该激光器工作在$λEQ1.55 $ mu @ m的波长下。外差传感用于空间获取和空间跟踪过程。选择了IF $ EQ 700 MHz的中频。波长和中频的定义要求开发新的位置检测器概念。象限检测器的功能是通过将反射金字塔顶部的叠加光束分成四个子光束来实现的。然后，这些光束被单独的针脚光电二极管检测到。 （在不使用望远镜的情况下）在1 mrad的探测器视场下获得的角分辨率小于5 $ mu @ rad。发射器激光器可以沿圆形轨道在横向平面内移动。微型计算机控制接收器的操作。在采集过程中，对不确定区域进行螺旋扫描。对于每个搜索位置，将扫描本地振荡器激光器，直到检测到700 MHz的拍信号为止。通过以下方式激活跟踪：首先，关闭模拟中频稳定环路；第二，通过从位置传感器信息计算所需的天线校正来关闭数字空间跟踪环路，从而实现平均跟踪误差$ POM 25 $ mu @ rad。
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