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Tunable Semiconductor Ultrashort Optic al Puse Generator

可调谐半导体超短光纤发生器

基本信息

批准号：
07555011
负责人：
KAMIYA Takeshi
金额：
$ 12.35万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

The most advanced technology of very large capacity optical communication is the combination of TDM (Time Division Multiplexing) and WDM (Wavelength Division Multiplexing). To test the equipment and components, it is required to develop a high performance optical pulse generator, satiffying conditions (I) pulse width around 1ps, (ii) tuning range 30-100nm. To realize high performance pulse generator, we have investigated three most important issues : (1) stability and chirp charactersitics of external cavity mode-locked semiconductor lasers ; (2) high quality, broad band antireflection coaitn design and fabrication ; (3) realization of tunable mode-locked semiconductor lasers operating at 1.3 and 1.5 um. As for the theory, it was succesfully explained that actively vs. passively mode-locked lasers have red-vs. blue-shift chirp characteristics due to the change of alpha parameters dominated by gain-vs. absorber-region. In addition the tendency of increased chirp due to carrier heating process was predicted. Secondly as for anti-reflection coating, a new design algorithm was proposed : in contrast to the conventional procedure starting with the optical admittance matching condition, the value function of wavelength bandwidth was introduced, and search for the maximum value function in design parmeter space was developed. Experimental trial achieved the band width of 30nm for reflectance less than 10^<-4>. Finally anti-reflection coating was formed for laser chips.Tunability ranging from 1322nm and 1352nm (30nm range) was achieved keeping the pulse width less than 20ps. It is a straightford procedure to compress it to 1 ps using fiber-optic compresser as the present authors have recently demonstrated.

目前最先进的超大容量光通信技术是时分复用（TDM）和波分复用（WDM）技术的结合。为了测试这些设备和器件，需要研制一台高性能的光脉冲发生器，满足以下条件：（1）脉宽在1 ps左右，（2）调谐范围在30- 100 nm。为了实现高性能的脉冲发生器，我们研究了三个最重要的问题：（1）外腔锁模半导体激光器的稳定性和啁啾特性;（2）高质量、宽频带的半导体激光器的设计和制造;（3）实现工作在1.3和1.5 μ m的可调谐锁模半导体激光器。从理论上成功地解释了主动锁模和被动锁模激光器由于增益区控制α参数的变化而产生的红移和蓝移啁啾特性。此外，还预测了载流子加热过程导致啁啾增大的趋势。其次，针对减反射膜层，提出了一种新的设计算法：与传统的从光导纳匹配条件出发的设计方法不同，引入了波长带宽的值函数，并在设计参数空间中搜索最大值函数。实验结果表明，在反射率小于10 μ m的情况下，其带宽可达30 nm<-4>。最后在激光器芯片上镀上增透膜，实现了1322 ~ 1352 nm（30 nm范围）的可调谐，脉宽小于20 ps。这是一个straightford程序压缩到1 ps使用光纤压缩器，本作者最近证明。