Abstract: An optical transmission system according to the present disclosure is a mode multiplexed optical transmission system using a multi-mode optical fiber in which a plurality of propagation modes propagate as a transmission line, the optical transmission system including an optical fiber transmission line (83) that includes an optical fiber with two or more propagation modes; and a plurality of mode converters (91) that are configured to generate mode coupling between at least one pair of the propagation modes, in which a variation in an installation interval of the plurality of mode converters (91) is equal to or less than a threshold value determined by the transmission line length (Lt) of the optical fiber transmission line (83).

Abstract: The invention concerns a single mode optical fiber having a core and a cladding, the core refractive index profile having a trapezoid-like shape. According to an aspect of the invention, the transition part of the trapezoid-like core refractive index profile is obtained by gradually changing a concentration of at least two dopants from a concentration in said center part of said core to a concentration in a cladding part adjacent to said core.

Abstract: A strain measurement device is provided. The strain measurement device includes at least one filiform strain sensor and a support of longilinear shape on which the filiform strain sensor is positioned. The strain measurement device also includes a stiffener.

Abstract: A compact print head enabling high-quality, high-speed printing is provided. A liquid ejecting head includes: a substrate, having elements that generate energy used to eject liquid from ejection openings, and provided with a liquid supply port that communicates with a surface of the substrate having the elements and an opposite surface thereof; a member, provided above the surface of the substrate, and having walls of a liquid flow path that communicates with ejection openings and the supply port; an insulating layer, provided so as to cover the supply port, and provided with a plurality of through-holes; and a conducting layer electrically coupled to the elements, and provided within the insulating layer so as to be insulated with respect to the liquid.