在全反射棱镜式激光陀螺中，环形激光器的合光输出特性直接影响激光陀螺的工作精度。利用激光器的模式理论，研究了在不同转速下，合光棱镜处的顺、逆时针光束干涉光场分布，分析了因光阑和合光棱镜加工、装配不当等因素造成的y方向合光角过大，高阶横模引起的干涉条纹歧化，以及多纵模对干涉光场分布的影响。实验研究了合光棱镜特性对激光陀螺测角精度的影响。

In total reflection prism laser gyro, the combiner output characteristics directly affect the gyroscope′s accuracy. By using the laser mode theory, the combination spot patterns of clockwise and anti-clockwise beams in different rotation speeds are analyzed. The interference spot abnormalities caused by unsuitably assembled diaphragm or combining prism, passed higher-order transverse mode, too big y direction angle, as well as multi-longitudinal modes are discussed. The relationship between beam combination quality and navigation accuracy in ring laser is studied experimentally.