Dotted groove type optical fiber cladding surface Bragg raster

Abstract

The invention discloses a dotted groove type optical fiber cladding surface Bragg raster, which is characterized in that the optical fiber cladding surface Bragg raster is arranged on the outer surface of the optical fiber cladding of the single mode fiber; the optical fiber cladding surface Bragg raster consists of a plurality of dotted grooves which cause the structural damage to the optical fiber cladding and have periodicity; and the center points of all dotted grooves are in the same line which is parallel with a center axis of the optical fiber. The dotted groove type optical fiber cladding surface Bragg raster is unique in structure, simple in manufacture method, miniaturized and fiber-optical. The invention has a characteristic sensitive to the outside medium, which is similar to the long period optical fiber bragg gating, has a high Q value factor and has a cross sensitivity effect which is much lower than the long period optical fiber bragg gating; the temperature, pressure and the strain sensitivity are higher than that of the traditional optical fiber Bragg raster; the raster zone of the optical fiber cladding has obvious double refraction effect and can be widely applicable to the fields like the biology, chemical engineering, medical science, the bioscience, etc.

Description

technical field [0001] The invention relates to an optical fiber grating, in particular to a Bragg grating on the cladding surface of a point-shaped groove type optical fiber. Background technique [0002] Information technology and sensor technology represented by optical fiber communication and optical fiber sensing technology have greatly promoted the progress of human society since the 1970s. Fiber Bragg gratings can be divided into two basic types according to the period size: fiber Bragg grating (ie, FBG, period less than 1 μm) and long-period fiber grating (period tens to hundreds of μm). At present, the most commonly used method for fabricating FBG is the phase mask method based on ultraviolet exposure, which requires the optical fiber material to be photosensitivity, and needs to increase its photosensitivity by carrying hydrogen. In 2007, I.Bennion of Aston University in the United Kingdom successfully wrote first-order, second-order and fourth-order Bragg grating...

AI Technical Summary

Problems solved by technology

However, there are many shortcomings in the method of chemical etching or side grinding of the FBG cladding, such as: the uniformity of the grating surface cannot be guaranteed, so the resonant spectrum of the grating is broadened, resulting in a decrease in the measurement accuracy in the sensor, or even unusable; The high mechanical strength makes it difficult to operate and easy to break during use; the process of chemical corrosion or side grinding takes a long time, the process is not easy to control, and the repeatability is not good

And at present, there is no relevant report both at home and abroad for the point-shaped groove type optical fiber cladding surface Bragg grating sensor proposed by the present invention.

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