Depicting a helix

Below is a simple example of a three-dimensional plot of a helix, which could represent circularly-polarized light, for example.

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

n = 1000
fig = plt.figure()

# Plot a helix along the x-axis
theta_max = 8 * np.pi
theta = np.linspace(0, theta_max, n)
x = theta
z =  np.sin(theta)
y =  np.cos(theta)
ax.plot(x, y, z, 'b', lw=2)

# An line through the centre of the helix
ax.plot((-theta_max*0.2, theta_max * 1.2), (0,0), (0,0), color='k', lw=2)
# sin/cos components of the helix (e.g. electric and magnetic field
# components of a circularly-polarized electromagnetic wave
ax.plot(x, y, 0, color='r', lw=1, alpha=0.5)
ax.plot(x, [0]*n, z, color='m', lw=1, alpha=0.5)

# Remove axis planes, ticks and labels
ax.set_axis_off()
plt.show()