An all-acrylic-based 1x2 plastic optical fiber (POF) coupler has been designed and manufactured. The optical device is based on a simple 1x2 Y-branch coupler design with a middle high index contrast waveguide taper and splitting ratio of 50:50. Device modeling has been performed using non-sequential ray tracing with an insertion loss of 4.68 dB. Machining of the optical device has been performed using EGX400 desktop engraver system. 1 mm milling tool size with machine spindle speed of 15,000 rpm has been utilized. A simple optimization on the milling process prior to machining improved the coupling surfaces between the POF fibers and the waveguide taper. POF fibers are inserted into the engraved u-grooves and are passively aligned to the waveguide taper. The measured insertion loss is 7.5 dB and with a splitting ratio of 50:50.
