Research on composite manufacturing method of semi-buried 1×32 optical splitter

In this paper, a composite manufacturing method was proposed to reduce the inner surface roughness of silica groove. Firstly, femtosecond laser was used to ablate the silica groove, then, a 5% concentration hydrofluoric acid solution was used to corrode the inner surface of silica groove. Secondly, Su8 adhesive was filled with the groove to form a semi-buried 1×32 optical splitter by doctor blade. The test results showed that the surface roughness Ra was less than 0.2 µm, and average insertion loss of output ports was 21.34 dB, moreover, the uniformity was less than 1.44 dB. Compared with the traditional femtosecond laser ablating method, surface roughness reduced by at least 0.1 µm, and the average insertion loss of output ports was reduced by 1.22 dB, and the uniformity was reduced by 0.41 dB. So, the composite manufacturing method improved the communication performance. It is satisfied with the requirements for optical interconnection in the electro-optical printed circuit boards.