Single and multi-stage high power optical isolators using a single polarizing element

An optical isolator for collimated laser radiation, the optical isolator comprising:

• a single polarizing element;
• at least one Faraday optical element comprising opposing optical faces through which there is a beam propagation axis;
• a first half-wave plate and a second half-wave plate disposed at the single polarizing element;
• a reflector at the single polarizing element;
• at least one reflective optical element disposed at the Faraday optic for reflecting radiation to provide an even number of passes through the at least one Faraday optical element;
• a magnetic structure capable of generating a magnetic field within the at least one Faraday optical element, wherein the magnetic field is aligned with the even number of passes along the beam propagation axis;
• wherein the optical isolator is configured to receive collimated input laser radiation, which passes through the single polarizing element and splits into a first polarization beam and a second polarization beam, and wherein the first polarization beam has a different polarization than the second polarization beam;
• wherein the first polarization beam and the second polarization beam each pass through the first half-wave plate;
• wherein the first polarization beam and the second polarization beam are reflected between the reflective optical element and the reflector, the first polarization beam and the second polarization beam each make at least four passes through the at least one Faraday optical element;
• wherein the first polarization beam and the second polarization beam pass through the second half wave plate, the single polarizing element and combine into collimated output laser radiation;
• and
• wherein collimated laser radiation is maintained throughout the optical isolator.