Fiber optical circulator

A method of differentiating paths for backward and forward light paths in an optical component, comprising the steps of:

• providing a first collimator and a second collimator opposite to each other;
• providing said first collimator with a first port and said second collimator with a second port;
• further providing the first collimator with a third port;
• defining a forward light path from the first port to the second port and a backward light path from the second port to the third port;
• providing first crystal, first subassembly, second subassembly and second crystal between said first collimator and said second collimator in sequence;
• and
• providing a third crystal between said first subassembly and said second subassembly with a reflection surface;
• wherein
• at least one of said forward light path and said backward light path is reflected by said reflection surface in said third crystal.

An optical circulator comprising:

• a first collimator and a second collimator opposite to said first collimator;
• said first collimator defining a first port, said second collimator defining a second port, said first collimator further defining a third port;
• a circulator core disposed between said first collimator and said second collimator,
• said circulator core including first and second crystals respectively confronting the first collimator and the second collimator, a third crystal positioned therebetween with a reflection thereof;
• and
• a forward light path being defined from the first port to the second port, and a backward light path being defined from the second port to the third port and different from the forward path;
• wherein
• the backward light path is reflected toward the first collimator by said reflection surface when said backward light path passes the third crystal, and an incident angle of the backward light path relative to the first collimator is determined by said reflection surface.

An optical circulator comprising:

• a first collimator and a second collimator opposite to said first collimator;
• said first collimator defining a first port, said second collimator defining a second port, said first collimator further defining a third port;
• a circulator core disposed between said first collimator and said second collimator,
• said circulator core including first and second crystals respectively confronting the first collimator and the second collimator, a third crystal positioned therebetween;
• and
• a forward light path being defined from the first port to the second port, and a backward light path being defined from the second port to the third port and different from the forward path;
• wherein
• the forward light path goes straight in one direction in the third crystal while the backward light path includes two sections pointing to different directions, respectively, in the third crystal.

An optical circulator assembly comprising:

• a first collimator and a second collimator opposite to said first collimator;
• said first collimator defining a first port, said second collimator defining a second port, said first collimator further defining a third port;
• a circulator core disposed between said first collimator and said second collimator,
• said circulator core including first and second crystals respectively confronting the first collimator and the second collimator, a third crystal positioned therebetween;
• and
• a forward light path being defined from the first port to the second port, and a backward light path being defined from the second port to the third port and different from the forward path;
• wherein
• the backward light path leaving from the third crystal has been directed toward an imaginary center axis of the whole assembly rather than away from said center axis, and thus no fourth crystal is required to be provided between the third crystal and the first crystal for inwardly deflecting outwardly deflected light occurring in said third crystal.