Abstract: Provided are an optical fiber, which has an out-coupling characteristic of high coupling efficiency and is advantageous in terms of size reduction, and an optical signal detecting apparatus, which has a high coupling rate and high degree of integration, using the optical fiber. The optical signal out-coupling optical fiber includes: a core in which a tilted Bragg grating or a long period optical fiber grating is formed; and a cladding that surrounds the core and in which at least one V-groove that totally reflects optical signals is formed, wherein optical signals are out-coupled by using the grating and the V-groove. The optical signal detecting apparatus includes: an optical signal out-coupling optical fiber; and an optical signal receiving device monitoring or detecting optical signals emitted from the optical fiber.

Abstract: The present invention provides a wavelength selective optical focusing device using the cladding-etching of an optical fiber and an optical module using the same. The wavelength selective optical focusing device includes a core for transmitting an optical signal therethrough; and a cladding layer surrounding the core and having a plurality of grooves formed in the outer circumferential surface thereof such that the grooves are changed at a designated rate, wherein an optical signal having a designated wavelength guided by the core is focused to the outside of the cladding layer by the grooves.

Abstract: Disclosed is a variable alignment-type optical fiber block in which alignment of waveguides can be changed according to temperature. The optical fiber block includes: a substrate having a receiving section formed at one end of the substrate, the receiving section having a predetermined volume; a ferrule seated in the receiving section, the ferrule having a hole in which an optical fiber is inserted; a first expandable block disposed between one side surface of the ferrule and an inner wall surface of the receiving section, which are opposed to each other, the first expandable block having a first thermal expansive coefficient; and, a second expandable block disposed between the other side surface of the ferrule and another inner wall surface of the receiving section, which are opposed to each other, the second expandable block having a second thermal expansive coefficient.

Abstract: Disclosed is a variable alignment-type optical fiber block in which alignment of waveguides can be changed according to temperature. The optical fiber block includes: a substrate having a receiving section formed at one end of the substrate, the receiving section having a predetermined volume; a ferrule seated in the receiving section, the ferrule having a hole in which an optical fiber is inserted; a first expandable block disposed between one side surface of the ferrule and an inner wall surface of the receiving section, which are opposed to each other, the first expandable block having a first thermal expansive coefficient; and, a second expandable block disposed between the other side surface of the ferrule and another inner wall surface of the receiving section, which are opposed to each other, the second expandable block having a second thermal expansive coefficient.

Abstract: Disclosed is an optical fiber block defining semicircular grooves thereon, and a method of making it. The optical fiber block comprises: an optical fiber cable having at least one core; a block base, including a body portion defining at least one semicircular groove across a top surface thereon, the quantity of semicircular grooves corresponding to the quantity of cores to be seated therein, the quantity of semicircular grooves corresponding to the quantity of cores to be seated therein; an adhesive applied to the block body so as to cover the optical fiber cable and the top surface of the block body; and, a cover disposed on the block body applied with the adhesive.

Abstract: An apparatus for manufacturing long period fiber gratings with low polarization dependence, and a long period fiber grating manufactured by the apparatus, are provided. This apparatus includes an optical fiber, one end of which has been rotated at least once with respect to the other end, an ultraviolet laser source, and an amplitude mask disposed over the optical fiber, for transmitting light emitted from the ultraviolet laser source at periodic distance intervals. In the manufacture of long period fiber gratings, the refractive index of an optical fiber core is perturbed by irradiating UV light to a twisted optical fiber or by irradiating UV light to an optical fiber which is rotating, so that isotropic perturbations in refractive index can be made when it is seen from the total length of the optical fiber.

Abstract: An apparatus and method of fabricating long-period fiber grating is provided. The apparatus includes a fiber, a string, one end of which is fixed, that is located over the fiber and vibrates at a predetermined vibration frequency, a vibrating portion, which vibrates the string at the vibration frequency, to which the other end of the string is connected, and a laser source for illuminating a laser on the string and the fiber, wherein the laser is periodically transmitted by the fiber due to the vibration of the string, and thus the refractive index of the fiber is changed. The long-period fiber grating is easily formed by locating the string, which vibrates at a predetermined vibration frequency, over the fiber and illuminating a laser to the resultant structure.