Effects Of Charge Dynamics And Device Parameters On The Resolution Of Electrooptic Spatial Light Modulators
Abstract
The theoretical resolution of an electrooptic spatial light modulator [such as the Pockels Readout Optical Modulator (PROM)] is a function of the electrostatic field distribution arising from stored point charges located within the active electrooptic crystal layer. The Fourier transform of the voltage distribution (which can be directly related to the modulation transfer function) is derived as a function of the charge location within the electrooptic crystal. In addition, the resultant analytic expression contains the dielectric constants of the blocking layers and electrooptic crystal, and the thicknesses of the three layers. This formulation allows the effects of charge trapping within the bulk of the electrooptic crystal to be modeled. In particular, the low spatial frequency response decreases linearly and the high spatial frequency response decreases exponentially with the distance of the point charge from the dielectric blocking layer/electrooptic crystal interface. Thus the overall sensitivity and resolution are degraded strongly by charge storage in the bulk away from the interface. Utilizing superposition, this formulation can be readily extended to accommodate arbitrary charge distributions arising from different exposure parameters. The implications of these results for device design and operation are discussed.
- Publication:
-
Active optical devices
- Pub Date:
- January 1980
- DOI:
- 10.1117/12.958106
- Bibcode:
- 1980SPIE..202..110O
- Keywords:
-
- Charge Distribution;
- Crystal Optics;
- Electro-Optics;
- Light Modulation;
- Modulators;
- Spatial Distribution;
- Dielectric Properties;
- Electric Fields;
- Fourier Transformation;
- Frequency Response;
- Image Resolution;
- Transfer Functions;
- Trapped Particles;
- Optics