短語詞組短語beam propagation path 光束傳播軌跡beam advancement path 光束傳布軌跡beam path path length 聲程Beam path location 聲程定位;聲束路徑位置beam path roller 轍尖移動滾輪beam path amendment 聲程修正Beam path location Slave 聲程定位beam path geometrical arrangement 光路幾何配置folding beam path 折疊光路 返回 beam path