Abstract: Provided is a method for providing a strain measurement value in a sensing optical fiber. The method may include outputting light to an optical fiber, in which the optical fiber includes a standard sensing optical fiber and a sensing optical fiber extending from the standard sensing optical fiber, in which the standard sensing optical fiber is accommodated inside an external environmental protection case, providing a strain measurement value in the sensing optical fiber based on Rayleigh scattered light reflected back from points of the optical fiber, and providing a final strain measurement value by compensating for an error caused by a change in light source in the strain measurement value in the sensing optical fiber.

Abstract: Disclosed are a distributed temperature sensing system using a multicore optical fiber and a method thereof. The distributed temperature sensing system using the multicore optical fiber is configured to use the multicore optical fiber for a typical distributed temperature sensing system (DTSS), analyze a signal by collecting, for all cores, Raman-scattered light that is backscattered by multiple cores, increase the size of the signal by the number of times corresponding to the number of cores, increase a signal-to-noise ratio (SNR) for the same sensing time, and increase a sensing distance.

Abstract: The present invention relates to an apparatus and a method for fiber optic perturbation sensing, in which it is possible to easily confirm whether an intrusion is occurred, an intrusion position, and an intrusion object by dividing an optical signal output from the optical signal generation unit, progressing the divided optical signals to optical paths having different lengths, coupling the divided optical signals to generate an sensing optical signal, outputting the generated sensing optical signal to the sensing optical fiber, dividing the sensing optical signal returning from the sensing optical fiber, progressing the divided sensing optical signals to the optical paths having different lengths, and coupling the divided sensing optical signals to generate an interference sensing optical signal.

Abstract: A photonic crystal light emitting device including: a light emitting diode (LED) light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first and second conductive semiconductor layers; and a first photon-recycling light emitting layer formed on one surface of the first conductive semiconductor layer, opposite to the active layer, wherein the first photon-recycling light emitting layer absorbs a primary light emitted from the LED light emitting structure and emits a light having a different wavelength from that of the primary light, and a photonic crystal structure is formed on an entire thickness of the first photon-recycling light emitting layer.

Abstract: A photonic crystal light emitting device including: a light emitting diode (LED) light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first and second conductive semiconductor layers; and a first photon-recycling light emitting layer formed on one surface of the first conductive semiconductor layer, opposite to the active layer, wherein the first photon-recycling light emitting layer absorbs a primary light emitted from the LED light emitting structure and emits a light having a different wavelength from that of the primary light, and a photonic crystal structure is formed on an entire thickness of the first photon-recycling light emitting layer.

Abstract: The present invention discloses a fiber Bragg grating sensor system.

Abstract: The invention provides an optical fiber laser apparatus. In the invention, an excitation light source outputs light of a given wavelength. A first optical fiber generates light of a plurality of wavelengths including light of a first wavelength by up-conversion from the output light. Also, a first resonator includes first and second mirrors provided on both ends of the first optical fiber, respectively. The first resonator selects the first wavelength light to output via the second mirror. Further, a second optical fiber amplifies an output of the first wavelength light incident from the first resonator. In addition, the first and second mirrors have higher reflexivity for the first wavelength light than the second wavelength light having higher gain per length of the optical fiber. The first fiber has a length set such that the first wavelength light oscillates preferentially over the second wavelength light.