| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device for phase modulation of coherent light with modulator cells comprising liquid crystal molecules, which achieves a large number of phase steps per modulator cell and whose switching delay is shorter than 1 ms. <P>SOLUTION: The device for phase modulation includes a spatial light modulator with a modulator matrix made up of regularly arranged controllable LC modulator cells, a light source means which illuminates the modulator matrix, and a control means for controlling the phase modulation in the LC modulator cells. The modulator matrix is designed in a configuration to comprise a controllable λ/2 plate which is disposed between two non-controllable λ/4 plates; the controllable LC modulator cells are of the PSS (polarization shielded smectic) liquid crystal type; each LC modulator cell can be controlled locally with a positive or a negative voltage value, depending on the actual phase values to be written, and the control means generate a globally constant phase offset for the phase values to be written in every other frame. <P>COPYRIGHT: (C)2010,JPO&INPIT |
