Overall efficiency of phase-only holograms for off-axis focusing and ratio α for different phase limited apertures.
| Aperture . | Overall efficiency (%) . | α . |
|---|---|---|
| C: −180° to 180° | 78.1 | 1.00 |
| D: −135° to 135° | 74.3 | 1.02 |
| E: −90° to 90° | 52.4 | 1.38 |
| F: −60° to 60° | 28.9 | 2.40 |
| G: −30° to 30° | 8.30 | 7.60 |
| Aperture . | Overall efficiency (%) . | α . |
|---|---|---|
| C: −180° to 180° | 78.1 | 1.00 |
| D: −135° to 135° | 74.3 | 1.02 |
| E: −90° to 90° | 52.4 | 1.38 |
| F: −60° to 60° | 28.9 | 2.40 |
| G: −30° to 30° | 8.30 | 7.60 |