ATRRI(5) File Formats Manual ATRRI(5)

atrri — AsToRia: Refractive Index

atrri is a plain text file format for storing a list of refractive indices that vary spectrally. Each refractive index is defined by 3 double precision floating point numbers: the wavelength in nanometers at which the index is set, followed by the real part and the imaginary part of the refractive index itself. Note that the listed refractive indices should be sorted in ascending order relative to their wavelength.

Characters behind the pound sign (#) are considered comments and are therefore ignored. Empty lines, that is, lines without characters or consisting solely of spaces and tabs, are simply ignored.

The file format is as follows:

⟨atrri⟩ ::= ⟨refractive-index⟩
...
⟨refractive-index⟩ ::= ⟨wavelength⟩ ⟨n⟩ ⟨kappa⟩
⟨wavelength⟩ ::= ⟨real⟩ # In nm
⟨n⟩ ::= ⟨real⟩ # Real part
⟨kappa⟩ ::= ⟨real⟩ # Imaginary part 

# Wavelength in nm    real part      imaginary part

300.000011921         1.740000010     0.469999999
310.000002384         1.741990328     0.469004273
319.999992847         1.743917465     0.468010038
329.999983311         1.745785475     0.467014253
339.999973774         1.748130083     0.465993971
349.999964237         1.750000000     0.464985400
359.999954700         1.750000000     0.463959038
369.999945164         1.750000000     0.462961257
379.999935627         1.750000000     0.461990029
389.999926090         1.750000000     0.460981935
399.999916553         1.750000000     0.459957659
August 30, 2023 UNIX