DENF

Diffraction Encircled Energy (fraction). This operand computes the fraction of diffraction encircled, ensquared, x only, or y only (enslitted) energy at a given distance from the reference point defined by Dist. For focal mode, the distance units are micrometers. For afocal mode, the distance units are afocal mode units.
The options and settings are identical to DENC, except Dist, which here is used as the distance at which the fraction of energy is desired. See also DENC, GENC, GENF, and XENC.
If the Dist value defined is beyond the point where the encircled energy is very close to 100%, the fraction returned is 1e+10; this is done for optimization efficiency.

GENF

Geometric Encircled Energy (fraction). This operand computes the fraction of geometric encircled, ensquared, x only, or y only (enslitted) energy at a given distance from the reference point defined by Dist. The options and settings are identical to GENC, except Dist, which here is used as the distance at which the fraction of energy is desired. See also GENC, DENC, DENF, and XENC.

XENF

Extended source encircled energy (fraction). This operand computes the fraction of extended source geometric encircled, ensquared, x only, or y only (enslitted) energy at a given distance from the reference point.
The Type is 1 for encircled, 2 for x only, 3 for y only, and 4 for ensquared. When using Type 2 or 3, the fraction of energy in the PSF is calculated in the [-x, x] or [-y, y] range respectively, centered on the chosen reference point. This is the full slit width given by Dist. For example, if Dist = 20 µm, the fraction of energy is calculated for a slit width of +/- 10µm.
Wave is the input wavenumber. 
The options and settings are identical to XENC, except Dist, which here is used as the distance at which the fraction of energy is desired.
See also XENC, GENC, GENF, DENC, and DENF.