Optical fiber alignment method and alignment device, and connection device

An optical fiber alignment method for moving a plurality of elements constituting an end surface of an optical fiber that is an object of alignment to arbitrarily set target positions by rotating the optical fiber around a central axis of the optical fiber, the method comprising:

• a reference image acquisition step of acquiring an end surface image of a reference optical fiber selected from a group of first and second optical fibers;
• a reference arrangement data measurement step of measuring and recording arrangement data relating to a plurality of elements constituting the end surface of the reference optical fiber as reference arrangement data from the end surface image of the reference optical fiber;
• an image acquisition step of acquiring an end surface image of the optical fiber;
• a measurement step of measuring arrangement data relating to the plurality of elements from the end surface image of the optical fiber;
• a calculation step of calculating an amount of deviation of each of the plurality of elements from a target element arrangement in which the plurality of elements should be located from a correspondence relationship of the elements between the arrangement data and the reference arrangement data for element identification recorded in advance;
• and
• an alignment step of performing alignment of the optical fiber by rotating the optical fiber around the central axis such that the amount of deviation is reduced, wherein
• under a setting in which the second optical fiber is selected as the object of alignment in a state where the element arrangement of the first optical fiber is fixed as the target element arrangement,
• in the image acquisition step, an end surface image of a non-selected optical fiber different from the reference optical fiber selected from the group of the first and second optical fibers is acquired as the end surface image of the optical fiber,
• in the measurement step, arrangement data relating to a plurality of elements constituting an end surface of the non-selected optical fiber is measured as the arrangement data of the optical fiber from the end surface image of the non-selected optical fiber,
• in the calculation step:
• a correspondence relationship between the plurality of elements of the non-selected optical fiber and a plurality of reference elements defined by the reference arrangement data is specified as the correspondence relationship on the basis of a comparison between the arrangement data of the non-selected optical fiber and the reference arrangement data, and
• an amount of deviation between an element arrangement constituted by the plurality of elements of the non-selected optical fiber and the target element arrangement is calculated, and
• in the alignment step, alignment between the first and second optical fibers is performed by rotating the second optical fiber around the central axis such that the amount of deviation is reduced, and an element arrangement of a plurality of elements constituting an end surface of the first optical fiber and an element arrangement of a plurality of elements constituting an end surface of the second optical fiber overlap each other.