All-fiber filter and preparation method thereof

Abstract

The invention discloses an all-optical-fiber filter based on a micro-optical-fiber theta-shaped resonant structure and a preparation method of the all-optical-fiber filter. The all-optical-fiber filter comprises a first micro-nanofiber (1), the micro-optical-fiber theta-shaped resonant structure (2) and a second micro-nanofiber (3), wherein the micro-optical-fiber theta-shaped resonant structure (2) is formed by the micro-nanofiber (1); a single-mode fiber is connected with one end of the micro-optical-fiber theta-shaped resonant structure (2) through the first micro-nanofiber (1) to lead out a reflected optical signal; the second micro-nanofiber (3) is coupled to the other end of the micro-optical-fiber theta-shaped resonant structure (2) to lead out a transmitted optical signal. According to the filter, the reflected and transmitted signals can be simultaneously output; multi-functional filtration can be achieved; the filter is high in tunability, compact in structure and flexible in design.

Description

technical field [0001] The invention relates to a micro-optical element, in particular to an all-fiber filter based on a micro-fiber "θ" resonant structure. Background technique [0002] Optical filters play an indispensable role in laser systems, optical communication systems, and optical sensing systems. In recent years, the development trend of the integration of laser systems, optical communication systems and optical sensing systems has led to the development of optical filters in the direction of miniaturization. The fiber ring resonator is an important component in the construction of optical filters. The reason is that, on the one hand, the fiber ring resonator is conducive to the realization of all-fiber optical systems, avoiding the insertion loss and coupling difficulties introduced by bulk devices; on the other hand, the fiber optic ring resonator The fringe fineness of the output spectrum of the ring resonant cavity is high and the free spectral range is adjust...

AI Technical Summary

Problems solved by technology

Although the ring single-junction resonator structure can realize optical ADD-DROP, the light in the resonator oscillates in one direction, there is no reflected optical signal, and each ring single-junction resonator can only realize one filtering function

In 2009, Professor Tong Limin and others invented an "all-fiber Fabry-Perot resonator based on micro-fiber loop mirror and its manufacturing method (Patent No. 200810163150.9)", which mainly consists of a Fabry-Perot resonator and two Composed of micro-nano fibers for input and output optical signals, although the light in this resonant structure is bidirectionally oscillated, the entire structure is equivalent to a Fabry-Perot cavity, which can only achieve the characteristics of a single comb filter, and uses three micro nanofiber

Professor Yang Zhongmin of South China University of Technology and others used a nested double-ring micro-resonator for filtering in "A Wavelength Tunable Miniature Single-mode Fiber Laser (Patent No. 201310068660.9)", and achieved single-mode laser output, but due to two micro The resonators are nested, it is difficult to adjust their size independently, and this nested double-ring resonator can only perform comb filtering

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