OPTICAL FILTER DEVICE

• Main Authors: IWASAKI, Katsuhiro, KIRIYAMA, Tomoaki, KITO, Katsuya
• Format: Patent
• Language: English; French; German
• Published: 20.09.2023
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

An optical filter device (10) includes: a first multi-core optical fiber (20) including a plurality of first cores; a first lens (30); an optical filter (40) which is rotated by a predetermined rotation angle about a rotation axis with respect to a plane orthogonal to an optical axis, and allows emission light beams exiting from the first lens (30) to pass therethrough; a second lens (50); and an optical fiber (60) including cores which the emission light beams exiting from the second lens (50) enter. When directions directed from a reference axis which passes through the optical axis and is parallel to the rotation axis toward one side and another side with respect to the reference axis along an orthogonal axis orthogonal to the optical axis and the reference axis are defined as a first orthogonal direction and a second orthogonal direction, respectively, a circumferential orientation of the first multi-core optical fiber is set so that, when an end face thereof is viewed along a center axis thereof, a separation distance is minimized. The separation distance is a sum of distances from the reference axis to first cores that are most separated away from the reference axis in the first orthogonal direction and the second orthogonal direction, respectively.