Electric optical fiber grating filter with switchable central wavelength

An electric optical fiber grating filter that can switch a central wavelength, the electric optical fiber grating filter at least comprising:

• a bimetal plate, which includes a first metal plate and a second metal plate joined together, wherein a thermal expansion coefficient of the first metal plate is smaller than a thermal expansion coefficient of the second metal plate;
• an optical fiber having an optical fiber grating, wherein the optical fiber is fixed along a surface of the first metal plate, and the bimetal plate bends when a temperature is changed, so that, a central wavelength of the optical fiber grating can be adjusted for a compensation on a shifting of the central wavelength;
• a spring, wherein a first end of the spring is connected to the second metal plate;
• a screw, which is connected to a second end of the spring and is used to adjust the number of windings of the spring, so as to optimize the compensation on the shifting of the central wavelength of the optical fiber grating caused by change of the temperature;
• a mobile structure, on which the screw is installed;
• and
• an electromagnetic switch, which is connected to the mobile structure to switch for stretching the spring to a first position or compressing the spring to a second position, so as to bend the bimetal plate between the two positions with respect to two quantities for the central wavelength.