Influence of TFT-LCD Pixels Structure on Holographic Encoding

The LCD is proposed as a new hologram loader with the advantage that the hologram image is controlled digitally with no any mechanical moving and rotating elements. Different hologram image can be readily introduced by changing the coded image displayed on the LCD. A basic problem in which LCD is a hologram image loader is limited LCD's pixel number. In CGH, the sample point number have great impact on holographic representation. So the choice of sample point number is very important. When the LCD is phase hologram image loader, the phase on hologram image was decided by phase distribution of recorded wavefront on LCD plane. In phase hologram encoding, the pixel spacing is sampling interval of recorded wavefront. Based on sampling theory, the frequency band can be obtained by spectrum analysis. For different wavefront shape, A model was developed for phase rate, the spectrum distribution was got, the phase rate which can be recorded by LCD can be got. A didactic example is included to illustrate the computational procedure.