CAJ | 학술논문

通过模分复用技术，将带有不同阶数轨道角动量的光波作为不同的信道，实现从另一维度极大地增加光通信的容量。光子轨道角动量的产生是这类技术的一个核心。基于有效介质理论，在光纤端面设计了特殊的螺旋结构，使光纤端面的有效折射率沿着顺时针或逆时针方向线性增加。当传导光波入射到该结构时，因方位角上的折射率不同而形成光程的差异，引起相应的相位延迟并形成相位波前的螺旋形结构，即产生带有轨道角动量的光波，采用FDTD方法模拟了轨道角动量的产生过程。
통과모분복용기술，장대유불동계수궤도각동량적광파작위불동적신도，실현종령일유도겁대지증가광통신적용량。광자궤도각동량적산생시저류기술적일개핵심。기우유효개질이론，재광섬단면설계료특수적라선결구，사광섬단면적유효절사솔연착순시침혹역시침방향선성증가。당전도광파입사도해결구시，인방위각상적절사솔불동이형성광정적차이，인기상응적상위연지병형성상위파전적라선형결구，즉산생대유궤도각동량적광파，채용FDTD방법모의료궤도각동량적산생과정。
Light waves with orbital angular momentum ( OAM) can be applied in the mode division multiplexing technology, which offers a new way to enlarge the communication capacity from another dimension.The generation of the OAM is the key of this technology.Based on the effective medium theory, we design a special structure at the end of the optical fiber:vortex structures which make the effective refractive index increases clockwise or counter-clockwise.When the incident light goes through this structure, the different refractive index will cause the different optical path and the corresponding phase delay alone the azimuthal angle, i.e.the OAM light.The above OAM generation process is simulated using an FDTD software.