Acrylic-based asymmetric and variable coupling ratio Y-branch plastic optical fiber coupler

摘要

Acrylic-based asymmetric and variable couplers have been developed using a single structured Y-branch design with a high-index-contrast waveguide taper and a void structure for fiber attenuation using the lateral displacement of two fibers. Device fabrication is performed by producing the device structure on an acrylic block using a computer numerical control (CNC) machine tool. The fabricated device has an excess loss of 5. 85 dB, while the coupling ratios are 56. 86 and 43. 14% when the device is operated as a 3 dB coupler. In the asymmetric coupler mode, the coupling ratio ranges from 44. 84 to 8. 01% for port 1 and 55. 16 to 91. 99% for port 2. The excess loss of this device varies from 5. 42 to 7. 64 dB. In the variable coupler mode, the coupling ratio ranges from 10. 09 to 32. 88% for port 1 and from 89. 91 to 67. 12% for port 2. The excess loss of the device varies from 5. 85 to 8. 49 dB.