# File:Mplwp dispersion curves.svg

Original file(SVG file, nominally 600 × 400 pixels, file size: 53 KB)

## Summary

Description
English: Plot of refractive index vs. wavelength of various glasses. For dispersion. The wavelengths in the gray-shaded portion correspond to the visible spectrum.
Date
Source Own work
Author Geek3
SVG development This plot was created with mplwp, the Matplotlib extension for Wikipedia plots.

## mplwp source code

The plot was generated with mplwp 1.7
#!/usr/bin/python
# -*- coding: utf8 -*-

import matplotlib.pyplot as plt
import matplotlib as mpl
import numpy as np
from math import *

code_website = 'http://commons.wikimedia.org/wiki/User:Geek3/mplwp'
try:
import mplwp
except ImportError, er:
print 'ImportError:', er
exit(1)

name = 'Mplwp_dispersion curves.svg'
fig = mplwp.fig_standard(mpl)
xlim = 0.3, 1.6; fig.gca().set_xlim(xlim)
ylim = 1.4, 1.9; fig.gca().set_ylim(ylim)
mplwp.set_bordersize(fig, 60.5, 26.5, 24.5, 48.5)
plt.gca().axvspan(0.38, 0.78, alpha=0.5, color='#aaaaaa')

# functions: https://refractiveindex.info
def n(l, coeff):
n21 = 0.
for a,b in coeff:
n21 += a * l**2 / (l**2 - b)
return sqrt(1. + max(0, n21))

# coefficients for the https://en.wikipedia.org/wiki/Sellmeier_equation
LASF9 = ((2.00030, 0.01214), (0.29893, 0.05387), (1.80692, 156.53083))
SF10 = ((1.62154, 0.01222), (0.25629, 0.05957), (1.64448, 147.46879))
F2 = ((1.34533, 0.00998), (0.20907, 0.04705), (0.93736, 111.88676))
BaK4 = ((1.28835, 0.00780), (0.13282, 0.03156), (0.94540, 105.96588))
BK7 = ((1.18319, 0.00722), (0.08718, 0.02682), (1.03134, 101.70236))
FK51A = ((0.97125, 0.00472), (0.21690, 0.01536), (0.90465, 168.68133))

x = np.linspace(xlim, xlim, 5001)
y = [n(xx, LASF9) for xx in x]
plt.plot(x, y, color='#0000cc')
plt.text(1.5, 1.84, 'Lanthanum dense flint LaSF9', ha='right')

y = [n(xx, SF10) for xx in x]
plt.plot(x, y, color='#0000cc')
plt.text(1.5, 1.71, 'Dense flint SF10', ha='right')

y = [n(xx, F2) for xx in x]
plt.plot(x, y, color='#0000cc')
plt.text(1.5, 1.608, 'Flint F2', ha='right')

y = [n(xx, BaK4) for xx in x]
plt.plot(x, y, color='#0000cc')
plt.text(1.5, 1.565, 'Barium crown BaK4', ha='right')

y = [n(xx, BK7) for xx in x]
plt.plot(x, y, color='#0000cc')
plt.text(1.5, 1.515, 'Borosilicate crown BK7', ha='right')

y = [n(xx, FK51A) for xx in x]
plt.plot(x, y, color='#0000cc')
plt.text(1.5, 1.45, 'Fluorite crown FK51A', ha='right')

plt.xlabel(r'wavelength $\lambda$ [$\mu m$]')
plt.ylabel(r'refractive index n')

plt.savefig(name)
mplwp.postprocess(name)


## Licensing

I, the copyright holder of this work, hereby publish it under the following license:   This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. You are free: to share – to copy, distribute and transmit the work to remix – to adapt the work Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

## File history

The following pages on the English Wikipedia use this file (pages on other projects are not listed):

## Global file usage

The following other wikis use this file:

• Usage on mk.wikipedia.org
• Usage on no.wikipedia.org
• Usage on zh.wikipedia.org