Linear-groove type optical fiber cladding surface Bragg grating

Abstract

The invention discloses a linear-groove type optical fiber cladding surface Bragg grating, and the grating is characterized in that the grating is disposed on the external surface of an optical fiber cladding of a single-mode optical fiber; the grating consists of a plurality of linear grooves; the plurality of linear grooves are distributed in the axial direction of the optical fiber in a periodic manner; the channels of the linear grooves are distributed in the peripheral direction of the optical fiber; The grating is unique in structure, is simple in manufacturing method, is miniaturized, and is based on fibers; the grating has a characteristic like that a long-period fiber bragg grating is sensitive to an external medium; the grating has a very high Q factor, and is greatly lower than the long-period fiber bragg grating in temperature / strain cross sensitivity effect; the grating is higher in temperature, pressure and strain sensitivity than a conventional fiber bragg grating; a grating region of the optical fiber cladding has a remarkable birefrigent effect; and the grating can be widely used for the biology, chemical, medical life science fields and other fields.

Description

technical field [0001] The invention relates to an optical fiber Bragg grating, in particular to a linear groove type optical fiber cladding surface Bragg grating. 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 gratings in the cor...

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, the linear groove type optical fiber cladding surface Bragg grating sensor that the present invention proposes, there is no relevant report both at home and abroad

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