Broadband Faraday isolator

An optical isolator for isolating a light source from reflections, comprising

• a first polarizer configured to accept light travelling in a forward direction from said light source, said first polarizer having an axis of polarization in a first orientation;
• a Faraday rotator and an optically active rotator,
• one of said rotators being configured to rotate the polarization of said forward travelling light from said first orientation to a second orientation, said second orientation being at a first angle relative to said first orientation,
• the other of said rotators being configured to rotate the polarization of said light in said second orientation into a third orientation, said third orientation being at a second angle relative to said second orientation;
• and
• a second polarizer positioned to accept the output of said rotators, said second polarizer having an axis of polarization aligned with said third orientation,
• wherein said optically active rotator compensates for the dispersion of said Faraday rotator to produce isolation over a wavelength range about a central wavelength, said compensation being achieved by configuring said optically active rotator and said Faraday rotator so that (i) said first and said second angles are different and (ii) the slope of said Faraday rotator's dispersion curve at said central wavelength is approximately identical to the slope of said optically active rotator's dispersion curve at said central wavelength.