Optical fiber grating tuner

Abstract

The present invention belongs to the field of tuning technology, and the optical fiber grating tuner includes one optical fiber grating and one piezoelectric ceramic element. The tuner is featured by that it also includes two support beams, each of which has one end fixed onto one side end of the piezoelectric ceramic element and the other end onto one end of the optical fiber grating, so as to form one bridge struture comprising optical fiber grating suspended over the piezoelectric ceramic element. The present invention has the features that the optical fiber grating is made to obtain the whole amount of deformation of the piezoelectric ceramic element by utilizing the amount of elongation of the piezoelectric ceramic element and that the suspended optical fiber grating will not produce chip. Furthermore, combining several piezoelectric ceramic elements can modulate optical fiber grating in AC or DC mode for wide application range.

Description

technical field [0001] The invention belongs to the technical field of fiber grating tuning, in particular to the structural design of a piezoelectric ceramic fiber grating tuner. Background technique [0002] Irradiating the photosensitive fiber with ultraviolet light can permanently change the refractive index of the fiber, and according to this effect, the fiber core is periodically exposed to obtain a fiber grating. Fiber grating is an all-fiber filter device, which can replace many original devices and is widely used in various fields of optoelectronics. Fiber Bragg Grating has many outstanding advantages, one of which is that its wavelength is easy to tune. The Bragg period and refractive index of the fiber grating can be changed by mechanical deformation or temperature change, thereby changing its reflection center wavelength. The tuning properties of fiber gratings can be used in laser wavelength tuning, optical filters, optical wave adding and adding (OADM), multi...

AI Technical Summary

Problems solved by technology

[0007] (1) The elongation of piezoelectric ceramics is small, and the maximum is only tens of microns, so the corresponding fiber grating tuning range is small (less than 1nm)

Moreover, if the fiber grating is directly bonded to the surface of the piezoelectric ceramic, since the piezoelectric ceramic is longer and the grating is shorter, the full deformation of the piezoelectric ceramic cannot be fully utilized.

[0008] (2) The fiber grating is directly glued to the surface of the piezoelectric ceramic. Uneven glue application and uneven strain of the piezoelectric ceramic itself will cause the fiber grating to chirp, that is to say, the axial stress distribution inside the grating is uneven, and the refractive index due to strain Change, so the refractive index distribution of the original fiber grating is changed, and its transmission spectrum or reflection spectrum is distorted

However, piezoelectric ceramics with a large amount of expansion and contraction generally have a large capacitance (up to the order of μF), so the AC impedance is too small, and the output range of the AC signal is limited.

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