Novel Tapered Optical Fiber Devices And Their Characteristics

Fiber optic taper technology is to melt and stretch the fiber and capillary tube to produce a taper at the melt,common taper devices are: fiber optic sensor,multi-core fiber fan-in fanout,fiber bundle,fiber coupler,etc.In this paper,combine the traditional taper drawing process and fiber drawing process to design a new tapered fiber device and a new tapered fiber device drawing system,which can reduce the connection loss between fiber bundle taper and multicore fiber and have better consistency.In this paper,the following work is carried out based on the new tapered fiber device:An integrated molding taper drawing process is designed,and two special noncircular mode field converters are designed under this process.The device is based on the fading core principle of double-clad fiber pulling taper,which can convert the fundamental mode spot in single-mode fiber into elliptical spot and triangular spot.The elliptical mode field converter consists of a perforated quartz capillary and an elliptical inner cladding fiber.The refractive index of the fiber core used is 1.467,the inner cladding The core refractive index is 1.467,the inner cladding is 1.462,and the outer cladding is 1.457.The perforated quartz capillary with an elliptical inner cladding is integrated into the cone,and the core is formed into an elliptical fiber at the waist of the cone.There are also triangular mode field converters,whose device structure as well as operating principle is the same as elliptical mode field converters.The mode-field converter is simple to fabricate and has a wide range of application scenarios with obvious effect on the conversion of light spots.A mode controller of multi-core fiber to few-mode fiber and its preparation scheme are designed,the device consists of low refractive index perforated capillary and multi-core fiber,the few-mode fiber is processed in the device cone by the fading core principle,and finally the simulation realizes the four-core fiber to excite and control the LP01,LP11,LP21 modes in the few-mode fiber,based on the working principle of the device,it can also excite the LP31,Based on the operating principle of this device,it can also excite higher order modes such as LP31 and LP41 in multimode fiber,which has potential applications in the field of mode division multiplexing.A new cone fiber device drawing system was designed and built according to the integrated molding cone drawing process,which has a large displacement stroke and can realize the quartz capillary to fiber drawing,and finally a seven-core fiber fan-in fan-out device was successfully processed by this system,and the length of the drawn seven-core fiber reached 53 cm with a maximum channel loss of 0.94 d B.In conclusion,this paper realized the processing of the new cone fiber device through integrated molding process,verified the feasibility of the new cone fiber device,combined with the new cone fiber device pulling system in the field of fiber pulling cone processing has some theoretical significance and practical application value.