Estimate the far-field divergence and maximum antenna gain of a Gaussian laser beam truncated by a circular aperture, or work out how large the spot will be at a given distance.
| Beam waist Radius, 1/e² intensity. | – |
| Minimum divergence Diffraction-limited, no clipping, half-angle, 1/e² intensity. | – |
| Maximum antenna gain Acc. to Klein & Degnan (1974), un-obscured. On-axis, without pointing error. | – |
| Effective divergence With clipping, half-angle, 1/e² intensity. | – |
| Beam diameter at given distance | – |
Please enter positive numbers for wavelength, aperture diameter and α.
Antenna gain versus truncation ratio α (0.7–1.5), for the wavelength and aperture diameter entered above. On-axis gain, without pointing error.
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