Loop optical circulator

A four-port loop optical circulator comprising:

• a first, a second, a third and a fourth optical ports for receiving optical beam therein;
• a plurality of optical components for guiding a beam received from said first port to project from said second port, for guiding a beam received from said second port to project from said third port, for guiding a beam received from said third port to project from said fourth port, and for guiding a beam received from said fourth port to project from said first port;
• and wherein said plurality of optical components includes
• a walk-off crystal for generating a vertical optical path displacement for a vertical polarized optical beam and for passing a horizontally polarized optical beam therethrough maintaining a same optical path,
• a vertical displacement means for shifting an optical path along a vertical direction with a predefined vertical displacement for an optical beam transmitted with a particular polarization, and
• wherein said vertical displacement means is adapted to transmit or receive said vertical polarized optical beam from said walk-off crystal, including vertically displacing the beam received from said fourth port and not vertically displacing the beam received from said second port or first port.

A four-port optical loop circulator comprising:

• a first, a second, a third and a fourth optical ports for receiving an optical beam therein;
• a plurality of optical components for guiding a beam received from said first port to project from said second port, for guiding a beam received from said second port to project from said third port, for guiding a beam received from said third port to project from said fourth port, and for guiding a beam received from said fourth port to project from said first port;
• and wherein said plurality of optical components includes
• a walk-off crystal for generating a vertical optical path displacement for a first polarized optical beam and for passing a second polarized optical beam therethrough maintaining the same optical path,
• a polarization beam splitter (“PBS”) coupled to the walk-off crystal and configured to reflect a beam received at a lower optical path from said fourth port along a vertical direction for generating a predefined vertical displacement, and not to reflect a beam received from any other port;
• and
• a right angle prism disposed at the predefined vertical displacement from the PBS and configured to reflect an optical beam received from the PBS in a substantially horizontal direction along an upper optical path to the walk-off crystal.

A four-port optical loop circulator comprising:

• a first, a second, a third and a fourth optical ports for receiving an optical beam therein;
• a plurality of optical components for guiding a beam received from said first port to project from said second port, for guiding a beam received from said second port to project from said third port, for guiding a beam received from said third port to project from said fourth port, and for guiding a beam received from said fourth port to project from said first port;
• and wherein said plurality of optical components includes
• a walk-off crystal for generating a vertical optical path displacement for a first polarized optical beam and for passing a second polarized optical beam therethrough maintaining the same optical path,
• a polarization beam splitter (“PBS”) coupled to the walk-off crystal and configured to reflect a beam received at a lower optical path from said fourth port along a vertical direction for generating a predefined vertical displacement without reflecting the beam received from said second port;
• a right angle prism disposed at the predefined vertical displacement from the PBS and configured to reflect an optical beam received from the PBS in a substantially horizontal direction along an upper optical path to the walk-off crystal;
• a first half wave plate for changing a state of polarization (“SOP”) of light from a first SOP to a second SOP to allow light to be reflected by the PBS;
• and
• a second half wave plate for changing the SOP back to the first SOP after reflection by the PBS.