Chirp fiber grating comb-shaped filter based on electromodulation

Abstract

The invention discloses a chirp fiber grating comb-shaped filter based on the electromodulation, belonging to the tunable fiber grating filter field, characterized by comprising resistance wires, a variable resistance, a linear chirp fiber grating, a thermal insulation plate, a plurality of fine V-shaped slots on the thermal insulation plate, a fiber fixing frame, an anode, a cathode, a bottom plate and a fiber. The linear chirp fiber grating is combined with the external heat source formed by the resistance wire, the temperature distribution on the fiber grating is changed by a partial heating way, thus compared with the left area and the right area, one of a plurality of partial areas in the axial direction of the chirp fiber grating has bigger temperature abrupt change, the phase shift is generated, therefore the filter has wide reflecting band with one or a plurality of narrowband transmission windows. The variable resistance value can be changed to adjust the current passing through the resistance wires, thus controlling the temperature of the resistance wires and obtaining ideal phase shift amount and filtering effect. In addition, the number of the resistance wires is corresponding to the number of the transmission windows, thus the number of the resistance wires is changed to perform the single-wavelength, double-wavelength and multi-wavelength filtering, and the conversion is convenient, while the position of the resistance wires is changed to perform the wavelength tuning of the transmission windows. The filter is simple and direct, has variable filtering wavelength and channel number, the wavelength tuning range is limited by the chirp fiber grating bandwidth and can be tens of nanometer.

Description

Technical field: [0001] The invention is a chirped fiber grating comb filter based on electrical modulation, and belongs to the field of tunable fiber grating filters. Background technique [0002] The filter is one of the key components of fiber grating sensing system and fiber communication system, and its practical application is getting more and more attention. In fiber grating sensor, the performance of tunable filter as demodulator directly determines the measurement The performance of the system, in the optical communication system, the filter plays an important role as the demodulation of the demultiplexed signal of the wavelength division multiplexing, and can also be used as the signal filter of the fiber amplifier, in the fiber laser, spectrum analysis There are also important applications. [0003] Tunable filters generally include (1) Mach-Zehnder filters, (2) acousto-optic tunable optical filters, (3) distributed feedback tunable filters, and (4) tunable Fabry filte...

AI Technical Summary

Problems solved by technology

[0004] With the development of optical communication and devices, these filters have disadvantages such as narrow tunable range, inconvenient operation, and high price, which cannot meet the needs in many occasions. However, the chirped fiber grating comb filter based on electrical modulation has a central Tunable wavelength, tunable wavelength interval, wide tuning range, narrow bandwidth, and easy operation are the filters required in many occasions

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