计算全息半色调编码技术的研究

Study of Half-Tone Coding Technology

论述了计算全息的基本原理及常用的编码方法,在罗曼型和博奇型编码的基础上,运用空间脉冲调制技术,提出了新型的编码技术———半色调位相型和标准型编码.半色调型编码用圆形通光孔代替矩形孔,以圆孔面积及位置来记录全息信息,改变了输出模式,减少了编码参数,为全息图的后期制作提供了一种新的方法.同时通过理论计算和结果分析证明了半色调位相型编码具有和罗曼型同样好的衍射效率,半色调标准型编码具有和博奇型一样大的带宽,但它们的图形数据减少一半.

In the paper, the fundamental principle and common coding technique of computer generated hologram(CGH) are discussed. Based on coding of Lohmann and Burch, a new type coding the half tone phase code and half tone standard code are put forward by using the space pulse modulation technique. The half tone code uses structure parameter of circular hole instead of rectangle hole and records the hologram information by area and position of circular hole, so it changes the output model, reduces the parameter and offers a new kind of method for making hologram in later stage. Meanwhile, by calculation and analysis, this paper proves that the diffraction efficiency of half tone phase code is as high as Lohmann and the bandwidth of half tone standard code is as large as Burch, but the graph data of half tone code are only half of them.