Writing method of wide bandwidth Gaussian low reflection fiber grating

Abstract

The invention discloses a writing method of a wide bandwidth Gaussian low reflection fiber grating. According to the method, firstly, a writing device of the wide bandwidth Gaussian low reflection fiber grating is built, an ultraviolet beam is focused by two cylindrical mirrors and then incident on a fiber through a phase mask to change the refractive index of a core, a low reflection fiber grating is written, the second cylindrical mirror is translated through an electronic control translation stage along the transmission direction of the ultraviolet beam to control the bandwidth of a Gaussian low reflection fiber grating, a spectrometer is utilized to measure the reflection spectrum of the low reflection fiber grating online to read the bandwidth, if the bandwidth does not meet requirements, the bandwidth reading is fed back to a computer, the electronic control translation stage is controlled by the computer through software, the second cylindrical mirror is translated by the electronic control translation stage, and the wide bandwidth Gaussian low reflection fiber grating satisfying the bandwidth requirements can be written. The method has advantages of high accuracy, fast response, automatic adjustment and high controllability.

Description

technical field [0001] The invention relates to the field of optical fiber grating production, in particular to a writing method of a wide-bandwidth Gaussian low-reflection optical fiber grating. Background technique [0002] In 1978, K.O. Hill of the Canadian Communications Research Center and his collaborators observed photon-induced gratings from optical fibers for the first time. Hill's early optical fiber used a sub-ion laser with a visible wavelength of 488nm to form a grating in the fiber core by increasing or prolonging the irradiation time of light injected into the fiber core. Later, G. Meltz and others used the interference fringes formed by a high-intensity ultraviolet light source to expose the optical fiber laterally and laterally to produce a refractive index modulation or phase grating in the optical fiber core. In 1989, the first fiber Bragg grating with a Bragg wavelength in the communication band was successfully developed. In 1993, Hill et al. propose...

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Problems solved by technology

At the same time, this also brings new problems. Since the light spot is only focused in the vertical direction, and the size of the light spot in the horizontal direction does not change, the bandwidth of the Gaussian low-reflection fiber grating written in this way is too narrow. Chirped low-reflection fiber gratings with wide bandwidth can be achieved by using a chirped phase mask. If a wide-bandwidth Gaussian low-reflection fiber grating is required, it cannot meet the requirements.

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