Same light splitting ratio and self-balancing optical fiber hydrophone time division multiplexing array light path composition method

Abstract

The invention relates to a formation method of an identical splitting ratio self-balancing type optical fiber hydrophone time division multiplexing array light path. When an optical fiber coupler and a fiber delay line are used for forming n paths of time division multiplexing light paths, the optical fiber couplers of identical splitting ratio are adopted to constitute the array light path. The optical fiber couplers in an input trunk are positively arranged and the optical fiber couplers in an output trunk are reversely arranged, leading the couplers passed by each hydrophone to be totally identical and the splitting ratio gone through by each hydrophone to be totally identical. Regardless of the splitting ratio of the optical fiber couplers, the additional loss and splitting ratio error caused by the couplers have the same effect on each hydrophone, and the light path made from the couplers has excellent power balance. The formation method has the beneficial effects of obtaining the time division multiplexing array of high performance and improving the power balance, time delay accuracy, interchangeability and expandability of the array.

Description

technical field [0001] The invention relates to the technical field of optical fiber hydrophone arrays, in particular to a method for constructing a time-division multiplexing array optical path of a self-balancing optical fiber hydrophone with the same splitting ratio. Background technique [0002] In the all-fiber line array sonar, the multiplexing optical path of the fiber-optic hydrophone array is a very important part. The array multiplexing optical path mainly includes two key technologies of time division multiplexing and wavelength division multiplexing. Among them, the key performances of time division technology, such as optical power balance, loss characteristics, delay accuracy, and scalability, have always been concerned by various research institutes. In the past, the time-division multiplexing optical path structure of traditional optical fiber sensing generally adopts two methods: one is to use a 50:50 split ratio coupler, such as figure 1 As shown, where C ...

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Problems solved by technology

At present, this method is widely used, but this method has several disadvantages: First, the number of couplers and fusion points that each hydrophone passes through is different (the more hydrophones are at the back), so the coupling The addition of the additional loss of the hydrophone and the loss of the fusion point will have an adverse effect on the power balance between each hydrophone; The longer the cumulative time delay of the hydrophone, the delay coil must be compensated; third, the splitting ratio of the coupler corresponding to each hydrophone is different, and there is no interchangeability between the couplers. It brings inconvenience to engineering applications; fourth, the time-score expansion is not strong, and any increase or decrease of any number of time-scores must redesign the split ratio

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