A study on 1×8 optical splitter packaging by laser micromachine

Abstract

In this paper, we proposed $1\times8$ optical power splitter packaging technique using a new low-cost passive alignment method for aligning the optical fiber with the PLC chip. Our new passive alignment method is to insert and align directly the single mode optical fiber with a corresponding waveguide of the PLC chip with the engraved U-grooves, which on the PLC chip are directly formed by ultrafast laser micromachine. This new passive alignment technique does not also require optical fiber array blocks with the PLC chip compared with the active method. In this way, it is very easy to put and make the alignment of single mode optical fibers with the PLC chip and the tolerance of the PLC devices to mechanical and environmental factors can be improved. The size of the machined U-groove is controlled within $\pm1\mum$ by ultrafast laser micromachine. The insertion loss and the return loss of the $1\times8$ optical splitter module fabiricatied by above our new technique is less than 11.0dB and more than 55dB, respectively. These results show that the passive alignment packaging technique in PLC optical splitter is excellent and provides a cost-effective packaging. In this study, however, we didn``t establish the good temperature stability for $1\times8$ optical splitter modules, which was the maximum change loss of 2dB as the temperature fluctuation. The stability of the insertion loss and the reflection loss depending on temperature change is of greatest importance for establishing the reliability of the $1\times8$ optical splitter modules. For future study, we need to establish the good temperature stability.