optics{ global_illumination{ } }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{maximum\;1}\)

This group is defining a spectrum of radiation illuminating modelled device.

Note

Lorentzian, Gaussian and Planck illumination spectra are fully additive, i.e. several of each can be added as needed in order to synthesize more complex illumination spectra.

Hint

Spectral data can be defined in the database (see also Optical groups in database{ } for list of predefined illumination spectra), in the database section of the input file, or imported from external files.

Important

The following general conditions must be satisfied when defining optics{ global_illumination{ } }

Maintained Keywords

The keywords below are available in at least one of currently published releases and are planned to be included also in the next release.

direction_x

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{integer}\)

  • values: {-1, +1}

  • unit: \(\mathrm{-}\)

Sets ascending \(+1\) or descending \(-1\) direction of illuminating radiation along the \(x\)-axis of simulation.

direction_y

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{integer}\)

  • values: {-1, +1}

  • unit: \(\mathrm{-}\)

Sets ascending \(+1\) or descending \(-1\) direction of illuminating radiation along the \(y\)-axis of simulation.

direction_z

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{integer}\)

  • values: {-1, +1}

  • unit: \(\mathrm{-}\)

Sets ascending \(+1\) or descending \(-1\) direction of illuminating radiation along the \(z\)-axis of simulation.

database_spectrum{ }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{maximum\;1}\)

Importing one of several spectra (solar spectra, CIE illuminants, coefficient, reflectivity, …), which can be found in the database file Optical groups in database{ }. Relative intensities (e.g. CIE illuminants) are normalized to 1.0 \(\mathrm{W/m}^2\)

database_spectrum{ name }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{character\;string}\)

Name of the illumination spectrum contained in the database to be used.

database_spectrum{ concentration }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [0.0, ...)

  • default: 1.0

  • unit: \(\mathrm{-}\)

Scaling factor multiplying the values of the spectrum.

import_spectrum{ }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{maximum\;1}\)

Importing spectrum from a file

Important

The following general conditions must be satisfied when defining import_spectrum{ }

  • The import{ } must be specified in the input file.

import_spectrum{ import_from }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{character\;string}\)

Reference name used in the import{ } group to label the imported spectrum.

import_spectrum{ cutoff }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{choice}\)

  • choices: yes; no

If set to yes, then the values of the spectrum which are outside the definition interval are set to zero. Otherwise, the spectrum is extrapolated as a constant with the value on the boundary of the imported data.

import_spectrum{ energy_spectrum }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{choice}\)

  • choices: yes; no

  • default: no

If set to yes, then the imported spectrum is assumed to be given as a function of energy. Otherwise, the spectrum is assumed to be given as a function of wavelength.

import_spectrum{ absolute_intensities }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{choice}\)

  • choices: yes; no

  • default: yes

If set to yes, then the values are directly imported without normalization. Otherwise, the values of the imported spectrum are normalized to the total intensity of the spectrum.

import_spectrum{ concentration }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [0.0, ...)

  • unit: \(\mathrm{-}\)

  • default: 1.0

Scaling factor multiplying the values of the spectrum.

constant_spectrum{ }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{maximum\;1}\)

Define illumination source with a constant radiation spectrum of the form

\[I(E) = \frac{I_0}{E_\mathrm{max}-E_\mathrm{min}}\]

constant_spectrum{ irradiance }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [0.0, ...)

  • unit: \(\mathrm{W/m^2}\)

Total intensity :math:` I_0 = int I(E)dE` of the spectrum, integrated from \(E_\mathrm{min}\) to \(E_\mathrm{max}\).

planck_spectrum{ }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{no\;constraints}\)

Define illumination source with a black-body radiation spectrum

\[I(E, T) = \frac{I_0}{\sigma T^4}\frac{2\pi E^3}{c^2h^3}\frac{1}{\exp{\left(\frac{E}{k_B T}\right)} - 1},\]

where \(\sigma\) is the Stefan–Boltzmann constant.

planck_spectrum{ irradiance }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [0.0, ...)

  • unit: \(\mathrm{W/m^2}\)

Total intensity :math:` I_0 = int I(E)dE` of the spectrum

planck_spectrum{ temperature }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-6, ...)

  • unit: \(\mathrm{K}\)

Temperature \(T\) entering the spectrum model

lorentzian_spectrum{ }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{no\;constraints}\)

Define illumination source with a Lorentzian radiation spectrum

\[I(E) = \frac{I_0}{\pi}\frac{\Gamma/2}{(E-E_0)+(\Gamma/2)^2}\]

Important

The following general conditions must be satisfied when defining lorentzian_spectrum{ }

lorentzian_spectrum{ irradiance }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [0.0, ...)

  • unit: \(\mathrm{W/m^2}\)

Total intensity :math:` I_0 = int I(E)dE` of the spectrum

lorentzian_spectrum{ wavelength }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [10.0, ...)

  • unit: \(\mathrm{nm}\)

Central wavelength \(\lambda_0\) of the spectrum

lorentzian_spectrum{ energy }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-6, ...)

  • unit: \(\mathrm{eV}\)

Central energy \(E_0\) of the spectrum

lorentzian_spectrum{ width }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-3, ...)

  • unit: \(\mathrm{nm}\)

Define the width of the spectrum in nm

lorentzian_spectrum{ gamma }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-6, ...)

  • unit: \(\mathrm{eV}\)

Define the width of the spectrum in eV

gaussian_spectrum{ }

Define illumination source with a Gaussian spectrum

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • items: \(\mathrm{no\;constraints}\)

\[I(E)=\frac{I_0}{\sqrt{2\pi}\sigma}\exp{\left[-\frac{(E-E_0)^2}{2\sigma^2}\right]}\]

Important

The following general conditions must be satisfied when defining gaussian_spectrum{ }

gaussian_spectrum{ irradiance }

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [0.0, ...)

  • unit: \(\mathrm{W/m^2}\)

Total intensity :math:` I_0 = int I(E)dE` of the spectrum

gaussian_spectrum{ wavelength }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [10.0, ...)

  • unit: \(\mathrm{nm}\)

Central wavelength \(\lambda_0\) of the spectrum

gaussian_spectrum{ energy }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-6, ...)

  • unit: \(\mathrm{eV}\)

Central energy \(E_0\) of the spectrum

gaussian_spectrum{ width }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-3, ...)

  • unit: \(\mathrm{nm}\)

Define the width of the spectrum in nm

gaussian_spectrum{ gamma }

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional\;within\;the\;group}}\)

  • type: \(\mathrm{real\;number}\)

  • values: [1e-6, ...)

  • unit: \(\mathrm{eV}\)

Define the width of the spectrum in eV

Examples

constant_spectrum{
        irradiance = 10000.0  # in [W/m^2], integrated as min_energy...max_energy
}

planck_spectrum{
    irradiance = 10000.0  # in [W/m^2], for complete(!) Planck spectrum; real value >= 0.0
    temperature = 5000.0  # real value >= 1e-6
}

global_illumination{
    direction_x = 1

    database_spectrum{
        name = "Solar-ASTM-G173-global"
    # name = "CIE-D75"
        concentration = 300 # e.g. 300 suns
    }
}

global_illumination{
    direction_x = 1

    import_spectrum{
        import_from = "filename"
        cutoff = yes  # yes/no: If yes, set values outside definition interval to zero.
                    # (default=?)
        absolute_intensities = yes  # yes/no (default: yes)
                                    # If no, spectrum does not contain absolute values,
                                    # normalize intensity to 1 [W/cm^2 nm^-1] before concentration
        concentration = 300 # e.g. 300 suns
    }
}

lorentzian_spectrum{
        irradiance = 10000.0  # in [W/m^2], for complete(!) Lorentzian spectrum; real value >= 0.0

        # Specify either wavelength and width, or ...
        wavelength = 500.0   # real value >= 10.0 in |unit:nm|
        width = 100.0        # real value >= 1e-3 in |unit:nm|

        # ... specify energy and gamma.
        energy = 2.5         # real value >= 1e-6 in |unit:eV|
        gamma = 1.0          # real value >= 1e-6 in |unit:eV|
}

gaussian_spectrum{
    irradiance = 1000.0  # in [W/m^2], for complete(!) Gaussian spectrum; real value >= 0.0

    # Specify either wavelength and width, or ...
    wavelength = 500.0   # real value >= 10.0 in |unit:nm|
    width = 100.0        # real value >= 1e-3 in |unit:nm|

    # ... specify energy and gamma.
    energy = 2.5         # real value >= 1e-6 in |unit:eV|
    gamma = 1.0          # real value >= 1e-6 in |unit:eV|
}