The special light beam modulator is a disc that rotates at high speed , symmetrically along its diameter is respectively arranged a slit and a small hole , the slit is used to modulate light beam , the small hole is used to the synchrosystem and measure speed of modulator 該調(diào)制器為一高速旋轉(zhuǎn)圓盤,其上沿軸向刻制細縫,在圓盤對稱位置開小孔;細縫用于調(diào)制光束,小孔用于系統(tǒng)同步及調(diào)制器轉(zhuǎn)速測定。