高频co2激光脉冲写入掺硼长周期光纤光栅的特性研究.docx

摘要
研究发现B—LPFG弯曲特性的方向相关性极弱,在损耗峰(1557nm处)幅值逐渐减小的同时,其短波方向即1540nm处出现了一个新的损耗峰,峰值逐渐增大,谐振波长向短波移动。
4、研究了高频C02激光脉冲在掺硼光纤上写入的长周期光纤光栅的扭曲特性。随着扭曲度绝对值的增大光栅的谐振峰幅值线性减小,波长则随扭曲度的增大向短波方向线性漂移。研究过程中发现,。
5、研究了高频C02激光脉冲在掺硼光纤上写入的长周期光纤光栅谐振波长的横向负载特性。同弯曲特性一样,其谐振波长的横向负载特性没有明显的负载方向相关性。损耗峰幅值随横向负载线性减小但其灵敏度的方向相关性较弱。
6、研究了高频C02激光脉冲在掺硼光纤上写入的长周期光纤光栅折射率特性。~,谐振波长随着折射率的增大线性减小,损耗峰幅值逐渐减小。
关键词:掺硼光纤,长周期光纤光栅,C02激光,耦合膜理论,特性研究
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ABSTRACT
AB STRACT
Long period fiber grating(LPFG)has developed into a critical passive device for wide-spread applications in munication and sensor method takes advantage of thermal shock effect in hiIgh frequency pulse energy
is SO focused and single heat time is short,which help to increase heat ,
we call write the LPFG by low this thesis,the fabricating method,formation
mechanism for LPFG characteristics and applications are fully studied.
High frequency C02 laser pulse controlled puter is a flexible method. Temperature stability of fiber grating by this way is more stable than that by ultraviolet written more laser energy is needed when we write LPFG High
absorption in cladding resulted in asymmetric refractive-index distribution within the
crOSS-section of the pared to single mode fiber,B-doped single mode fiber OWns lower critical relatively lower heating temperature,we call make the silica structure ,the core index Can be changed with a small amount of laser energy and didn’t affect the cladding characteristics are
different with LPFG written on single mode fiber by high frequency C02 laser pulse.
Based on the method of LPFG written on single mode fiber by hi曲frequency C02 laser pulse,we fully studied the characteristics of LPFG written on B—doped fiber by lligh frequency C02 laser main work is provided as follows:
fully introduce fabrication methods of LPFG and the method of LPFG
written on B-doped fiber by high