Cylindrical Vector Beam Optical Interconnection For High Performance Computing

With the continuous development of high performance computer(HPC),the demand for interconnected capacity is growing.The existing optical interconnect technology has become an obstacle to the development of HPC,so it is necessary to develop optical interconnection multiplexing technology between nodes.Cylindrical vector beam(CVB)multiplexing have shown great potential for increasing data capacity in free space and fiber optical communications.For CVB fiber optical communication systems,(de)multiplexers and the optical fiber supporting high-order mode transmission are the key issues.However,there is still a lack of high-efficiency and large dynamic range CVB(de)multiplexers and fiber supporting high-order CVB mode transmission.In this thesis,the following works regarding the CVB multiplexing communication have been done: 1.anisotropic optical geometric transformation sorting CVB;2.High-resolution CVB sorting based on anisotropic fan-out optical geometric transformation;3,silicon-based metasurface fan-out optical geometric transformation sorting CVB;4,CVB mode multiplexing communication in air-core photonic crystal fiber(PCF).The main contents of this thesis include:1.The research of anisotropic optical geometric transformation sorting CVB.The CVB can be decomposed into two orbital angular momentum(OAM)states of left and right circular polarization with conjugated topological charges.The optical geometric transformation can efficiently sort OAM,but cannot sort CVB.The anisotropic material independently modulates the left and right circular polarization components of the CVB.Therefore,we propose an anisotropic optical geometric transformation sorting CVB.The anisotropic optical geometric transformation device fabricated by photo-aligned liquid crystal has a total pixel number of 768×768 with a pixel size of 11.7 ?m.the CVB is focused into a long spot by anisotropic optical geometric transformation with a lateral displacement proportional to the order of the input CVB.In the experiment,the CVB detection of the order from-10 to +10 with an efficiency as high as 61.7%.Also,the anisotropic optical geometric transformation device is applied to the coaxial CVB multiplexing communication system of free space and few mode fibers.The CVB multiplexing communication system has the potential for the next generation high-capacity short-distance optical interconnections application.2.High-resolution CVB sorting based on anisotropic fan-out optical geometric transformation.Although anisotropic optical geometric transformation has shown high efficiency and large dynamic range for CVB sorting,the spatial resolutions of the sorting results is insufficient to separate adjacent CVBs,and the shape of the sorting result is an irregular long strip.A fan-out structure is introduced into the anisotropic optical geometric transformation to improve the resolution of the CVB sorting result,and a cylindrical lens is used to convert the light spots to Gaussian like shaped spots.The high-resolution CVBs sorting from-5 to +5 orders are demonstrated experimentally.The sorting result is Gaussian like shaped spots and simultaneously coupled to the multimode fiber array with an insertion loss less than 8.7 dB,and an adjacent mode crosstalk of less than-6 dB.Compare with the long spot,the Gaussian spot focusing by cylindrical lens reduce 7 dB fiber coupling loss.We demonstrate four channels coaxial CVB multiplexing communication experiment in free space and few mode fibers.Anisotropic fan-out optical geometry transformation can effectively improve the resolution of CVB sorting,and demonstrated multiple channel inputs and simultaneous output of multiple channels in experiments.3.Silicon-based metasurface fan-out optical geometric transformation sorting CVB.The Silicon-based metasurface technology has the advantages of high fabrication precision and small feature size for integrated anisotropic fan-out optical geometric transformation.Elliptical nanorod structures with geometric phases are designed by theoretical analysis and simulation.The elliptical nanorods are used as pixels in the fan-out optical geometry transformation,and the hologram is realized by controlling the orientations of the elliptical nanorod array.The metasurface device size is 1.6mm × 1.6mm,the pixel size is 0.8 ?m,and the working distance of the whole system is less than 50 mm.Numerical simulation shows that the silicon-based metasurface fan-out optical geometric transformation can efficiently sorting CVB.4.Research on multiplexing communication of CVB modes in air-core PCF.Compared with the solid core optical fibers,air-core fiber has larger effective refractive index difference and smaller transmission delay,which is more suitable for optical interconnection for high performance computer.The simulation shows that the PCF supports CVB transmission from ±1 order to ±4 order.Moreover,the effective refractive index difference of the air-core PCF is one order of magnitude larger than that of the few mode fibers,which can effectively reduce the crosstalk of different modes inside the optical fiber.We demonstrate the transmission of ±1 to ±4 order CVB in 8.25 m air-core PCF with a mode purity of 76.5%.We demonstrate coaxial CVB multiplexing communication in air-core PCF with the crosstalk of less than-9 dB,and the measured bit error rate is lower than the forward error correction threshold.