Description:

This module calculates the real and imaginary part of the dielectric function, real and imaginary part of the refractive index for different metals using either Drude model (D) and Lorentz-Drude model (LD). The parameters are obtained from Rakic et al. This module is inspired by LD.m http://www.mathworks.com/matlabcentral/fileexchange/18040-drude-lorentz-and-debye-lorentz-models-for-the-dielectric-constant-of-metals-and-water

##Reference:

Rakic et al., Optical properties of metallic films for vertical- cavity optoelectronic devices, Applied Optics (1998)

##Example: To use in other python files

    from LD import LD # Make sure the file is accessible to PYTHONPATH or in the same directory of file which is trying to import
    import numpy as np
    lamda = np.linspace(300E-9,1000E-9,100) # Creates a wavelength vector from 300 nm to 1000 nm of length 100
    gold = LD(lamda, material = 'Au',model = 'LD') # Creates gold object with dielectric function of LD model
    print gold.epsilon_real
    print gold.epsilon_imag
    print gold.n
    print gold.k
    gold.plot_epsilon()
    gold.plot_n_k()

##INPUT PARAMETERS for LD:

   lambda   ==> wavelength (meters) of light excitation on material. Numpy array

   material ==>    'Ag'  = silver
                   'Al'  = aluminum
                   'Au'  = gold
                   'Cu'  = copper
                   'Cr'  = chromium
                   'Ni'  = nickel
                   'W'   = tungsten
                   'Ti'  = titanium
                   'Be'  = beryllium
                   'Pd'  = palladium
                   'Pt'  = platinum

   model    ==> Choose 'LD' or 'D' for Lorentz-Drude or Drude model.