A tunable flat-top narrow-band optical filter based on mems

Abstract

The invention discloses a tunable flat top narrow-band type optical fiber based on an MEMS. The optical fiber comprises a twin-core optical fiber collimator, a beam expanding prism, a transmissive phase grating, a beam shrinking prism and an MEMS micromirror, wherein one tail fiber of the twin-core optical fiber collimator is a single mode optical fiber, and the other tail fiber is a multimode optical fiber or a less-mode optical fiber; DWDW optical signals are input from the single mode optical fiber of the twin-core optical fiber collimator and become collimated light beams, beam expanding is carried out on the DWDW optical signals through the beam expanding prism, then the transmissive phase grating conducts chromatic dispersion and light division on the DWDW optical signals, the DWDW optical signals enter the MEMS micromirror after being compressed through the beam shrinking prism, and only channel optical signals which are of vertical incidence can return to the twin-core optical fiber collimator along an original way and are output of the multimode optical fiber or the less-mode optical fiber. The optical signals with different wave lengths can be output by changing the turning angle of the MEMS micromirror, and the tunable filtering function is achieved. Since the multimode optical fiber or the less-mode optical fiber serves as an output end, flat top spectral response can be achieved, and the tunable flat top narrow-band type optical fiber is applied to downlink detection of wave lengths in a DWDW system.

Description

technical field [0001] The invention belongs to the technical field of optical communication, and more specifically, relates to a tunable flat-top narrow-band optical filter based on a microelectromechanical system (MicroElectroMechanicalSystem, MEMS), in particular to a single-mode fiber input / multimode fiber (or The tunable flat-top narrow-band optical filter output by the few-mode fiber) can be widely used in wavelength drop detection in dense wavelength division multiplexing (DenseWavelengthDivisionMultiplexing, DWDM) systems. Background technique [0002] In recent years, with the development of DWDM technology, the wavelength band used in the optical communication system has been continuously expanded, and the channel spacing has become smaller and smaller. This requires that the tunable optical filter not only has a large tuning range and narrow bandwidth, but also hopes that it can It has a flat-top response characteristic, enabling fast and precise alignment of chan...

AI Technical Summary

Problems solved by technology

These filters all use single-mode fiber as the input / output end, which can obtain better flat-top response, but it is difficult to meet the requirements of large tuning range and narrow bandwidth at the same time, and the manufacturing process is often complicated and the cost is high.

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