Study on fiber tail pipe packaging technology of microwave-to-optical converter

Microwave photonics is a new technology that uses optical methods to generate, transmit and process microwave signals. Compared with the traditional cable transmission technology, optical fiber has the advantages of low loss, wide bandwidth, light weight, electromagnetic interference resistance and so on. It is a good transmission medium, which has aroused great interest of researchers. However, the interface between microwave devices and optical fibers is a bottleneck to be broken. This paper proposes an effective tail pipe packaging method. The designed optical collimator is coupled with the internal optical path and packaged in the tail pipe of the device, which is fixed by gluing process. Through two upgrades to the tail pipe, the lateral tensile strength of the fiber was increased by more than 120%. Two models were designed to analyze the thermal stress of the tail pipe and to verify the effect of packaging mode on the coupling displacement of the fiber collimator. The results show that the influence of the two packaging models on the coupling displacement is 0.47 um and 0.56 um respectively, which is much smaller than the tolerance of optical path. This packaging method can greatly reduce the risk of fiber breakage and improve the reliability of the converter without changing the performance of the converter.