Polymer large core optical splitter 1x2 Y for high-temperature operation

The design, fabrication and measurement of the properties of the large core 1x2 Y optical planar splitters for high-temperature operation are demonstrated. The splitters were designed by the beam propagation method optimized for operation wavelengths 650nm and for assembling with optical fibre having core diameter 600 mu m and cladding 630 mu m. The splitters consisted of optical glue core and cladding layers made of Cyclo Olefin Polymer. The applied materials allowed for higher operating temperatures (up to 120 degrees C) than standard splitters made of acrylate plastic (up to 80 degrees C). The splitters show optical losses lower than 4.0dB at 532nm/650nm, 2.6dB at 850nm, 3.4dB at 1300nm and 5.1dB at 1550nm at room temperature. The optical losses measured in the thermal shock test chamber at temperatures up to 120 degrees C showed that the best sample had losses lower than 4.2dB at 850/1300nm, 4.6dB at 532nm and 7.6dB at 650nm. Such splitters would be very useful in places with elevated temperatures, for instance in engine parts where the expected temperature can reach as high as 120 degrees C