Four-channel signal-receiver optical subassembly module using a thin-film filter-based coarse-wavelength-divisionmultiplexing demultiplexer for monitoring 22.9-kV XLPE cable joints

We propose a four-channel signal-receiver optical subassembly (ROSA) for partial-discharge signal transmission using a coarse-wavelength-division multiplexing (CWDM) thin-film filter (TFF). The proposed fourchannel ROSA consists of an ultrasmall-factor-based demultiplexer module, which is fabricated with a parallel optical block, four CWDM TFFs, and four 28-Gbps integrated positive-intrinsic-negative photodiode blocks. The partial discharge on a 22.9-kV XLPE cable joint was successfully measured using the proposed module with phase-resolved partial-discharge analysis and a pulsediagnosis system. The experimental results demonstrated the feasibility and effectiveness of the proposed ROSA module for the diagnosis of partial discharge, which is important for monitoring electric power facilities.