Method for assembling optical isolator and method for measuring isolation

A method for assembling an optical isolator, comprising the steps of:

• constructing a measuring system in which a light source, a lens system, a polarizer, an analyzer, and a light receiver are arranged in this order, and light projected from said light source and then transmitted through said lens system, said polarizer, and said analyzer, is received by said light receiver;
• arranging optical elements for constituting said main body of the optical isolator between said polarizer and said analyzer;
• measuring a maximum value and a minimum value in levels of the light received by said light receiver while said analyzer is rotated every time said components are rotated and stopped, thereby to calculate a ratio of said minimum value to said maximum value;
• and
• adjusting rotation positions of said respective optical elements to the rotation position of said optical elements where a ratio of said maximum value to said minimum value becomes maximal.

A method for measuring isolation of an optical isolator, comprising the steps of:

• constructing a measuring system in which a light source, a lens system, a polarizer, an analyzer, and a light receiver are arranged in this order, and light projected from said light source and then transmitted through said lens system, said polarizer, and said analyzer, is received by said light receiver;
• arranging said main body of the optical isolator between said polarizer and said analyzer;
• measuring a maximum value and a minimum value in levels of the light received by said light receiver while said analyzer is rotated;
• and
• setting as isolation a value indicative of a ratio of said minimum value to said maximum value in unit of dB.