Nano-Printed Spiral Phase Plate on Fiber Ferrules for Modal Filtering in Free-Space Optical Communications
- Fritsch, Samuel [ Montana State University: Physics ]
- Dugre, Joshua [ Montana State University: Physics ]
- Mohan, R. Krishna [ Montana State University: Physics ]
In this work, we demonstrate the fabrication as well as immediate application of 3D printed spiral phase plates on the ends of FC/PC fiber adapter ferrule tips using a NanoOne 1000 two-photon polymerization 3D printer from UpNano. The spiral phase plates were fabricated to alter the orbital angular momentum of incoming light, and a direct application of modal filtering in an indoor, short-range, free-space optical communication link was shown. The mode conversion quality of six different 3D printed spiral phase plates on ferrule tips is presented. An l=4 and an l=-4 spiral phase plate were chosen to demonstrate the ability to suppress an aggressing Gaussian signal in a free-space communication link, with the l=4 being printed on a FC/PC ferrule tip used as the transmit, and the l=-4 printed on a glass slide in the receive architecture of the system. Multiple iterations of the experiment were performed, and it was found that the 3D printed structures were able to suppress the aggressing Gaussian beam on average by approximately 32.7 dB and allowed for error-free communication at 10 Gbps on a vortex beam with the co-propagating aggressor at an identical wavelength to the communication link.