飞速增长的光通信容量需求推动着光纤技术的发展,基于空分复用技术的多芯光纤作为突破传统单模光纤容量限制的方法引起了广泛的关注.本文将纤芯异质结构与低折射率沟槽结合,设计了1种具有低串扰的十九芯单模光纤结构,该结构由环绕沟槽的...飞速增长的光通信容量需求推动着光纤技术的发展,基于空分复用技术的多芯光纤作为突破传统单模光纤容量限制的方法引起了广泛的关注.本文将纤芯异质结构与低折射率沟槽结合,设计了1种具有低串扰的十九芯单模光纤结构,该结构由环绕沟槽的3种不同参数的纤芯按正六边形排布构成,在C+L波段能实现稳定单模传输.研究结果表明:在波长为1.55μm时,通过在沟槽中进行掺氟处理,可以使光纤的芯间串扰降低至–39.52 d B/100 km.此外在弯曲半径为100 mm时,弯曲损耗为–7.7×10^(–5) d B/m且色散低于24 ps/(nm·km).纤芯中基模的有效模场面积约为80μm2,有利于降低非线性效应.与传统单模光纤及单沟槽同质结构光纤相比,该结构具有更低的串扰、更好的抗弯曲性能和更大的模场面积.本文设计的光纤适用于空分复用系统中远距离大容量的传输.展开更多
Decoherence of fiber laser sources is of great importance in imaging applications,and most current studies use ordinary multi-mode fibers(MMFs).Here,a newly designed single-trench fiber(STF)is investigated to reduce t...Decoherence of fiber laser sources is of great importance in imaging applications,and most current studies use ordinary multi-mode fibers(MMFs).Here,a newly designed single-trench fiber(STF)is investigated to reduce the spatial coherence of fiber light source and compared with MMFs.By bending two fibers with different turns,speckle contrast of a 0.8-m-long STF can be reduced from 0.13 to 0.08,while a 0.8-m-long MMF shows an inverse result.Through speckle contrast and decoupling-mode analysis,the reason of this inverse trend is revealed.Firstly,the STF supports more modes than the MMF due to its larger core diameter.Secondly,mode leak from the first core of the STF can couple to the second core when bending the STF.Thus,power distribution among high and low-order modes become more even,reducing the spatial coherence considerably.However,in the MMF,high-order modes become leaky modes and decrease slightly when bending the fiber.This work provides a new method to modulate coherence of light source and a new angle to study decoherence principle using special fibers.展开更多
文摘飞速增长的光通信容量需求推动着光纤技术的发展,基于空分复用技术的多芯光纤作为突破传统单模光纤容量限制的方法引起了广泛的关注.本文将纤芯异质结构与低折射率沟槽结合,设计了1种具有低串扰的十九芯单模光纤结构,该结构由环绕沟槽的3种不同参数的纤芯按正六边形排布构成,在C+L波段能实现稳定单模传输.研究结果表明:在波长为1.55μm时,通过在沟槽中进行掺氟处理,可以使光纤的芯间串扰降低至–39.52 d B/100 km.此外在弯曲半径为100 mm时,弯曲损耗为–7.7×10^(–5) d B/m且色散低于24 ps/(nm·km).纤芯中基模的有效模场面积约为80μm2,有利于降低非线性效应.与传统单模光纤及单沟槽同质结构光纤相比,该结构具有更低的串扰、更好的抗弯曲性能和更大的模场面积.本文设计的光纤适用于空分复用系统中远距离大容量的传输.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974071 and 61635005)in part by Sichuan Science and Technology Program,China(Grant No.2018HH0148)。
文摘Decoherence of fiber laser sources is of great importance in imaging applications,and most current studies use ordinary multi-mode fibers(MMFs).Here,a newly designed single-trench fiber(STF)is investigated to reduce the spatial coherence of fiber light source and compared with MMFs.By bending two fibers with different turns,speckle contrast of a 0.8-m-long STF can be reduced from 0.13 to 0.08,while a 0.8-m-long MMF shows an inverse result.Through speckle contrast and decoupling-mode analysis,the reason of this inverse trend is revealed.Firstly,the STF supports more modes than the MMF due to its larger core diameter.Secondly,mode leak from the first core of the STF can couple to the second core when bending the STF.Thus,power distribution among high and low-order modes become more even,reducing the spatial coherence considerably.However,in the MMF,high-order modes become leaky modes and decrease slightly when bending the fiber.This work provides a new method to modulate coherence of light source and a new angle to study decoherence principle using special fibers.
