硅基混合波导中超连续谱的产生及其在全光量化与编码中的应用研究

Supercontinuum (SC) source has significant applications in optical communication and all-optical signal processing. The integrated highly coherent and octave-spanning SC source with fast response time and low power consumption can be achieved with silicon-based photonic technology. Therefore, it has a crucial meaning to investigate the generation of highly coherent and octave-spanning SC in silicon-based hybrid waveguides and its application in all-optical quantization and coding. In this project, with new principle of silicon-based photonic devices with special structure, the degradation mechanism on the SC coherence induced by modulation instability and noise in the anomalous dispersion region of silicon-based hybrid waveguides will be investigated, and the schemes on self-similar pulse compression and highly coherent and octave-spanning SC generation will be proposed. The suitable waveguide materials need to be selected, the theoretical model on the ultrashort pulse propagation in the silicon-based hybrid waveguides will be established, and the waveguide structure will be designed and optimized to achieve highly coherent and octave-spanning SC. Based on the SC generated, all-optical quantization and coding schemes will be proposed, and the integrative experimental platform on the pulse compression, SC generation, and quantization and coding will be established. It is believed that the research findings of this project can enrich the nonlinear theory of silicon-based hybrid waveguides, provide new method and way for highly coherent and octave-spanning SC generation and its application in all-optical quantization and coding, and promote the development of integrated all-optical signal processing technology and device.

超连续谱(SC)源在光通信和全光信号处理等领域具有重要的应用。利用硅基光子技术可实现响应快、功耗低、易于集成的高相干、倍频程SC源。因此，研究硅基混合波导中高相干、倍频程SC的产生及其在全光量化与编码方面的应用具有重要意义。本项目拟采用硅基光子特殊结构器件的新原理，研究在硅基混合波导反常色散区中调制不稳定性和噪声对SC相干性的劣化机理，提出基于硅基混合波导的自相似脉冲压缩和高相干、倍频程SC实现的方案；选取合适的波导材料，建立超短脉冲在硅基混合波导中传输的理论模型，设计并优化波导结构，以实现高相干、倍频程SC；基于产生的SC，提出实现全光量化与编码的方案，建立脉冲压缩、SC产生、量化与编码一体化的实验平台。本项目的研究成果将丰富硅基混合波导的非线性理论，为高相干、倍频程SC实现及其在全光量化与编码方面的应用提供新方法和新途径，并将有效地促进可集成的全光信号处理技术与器件的发展。

硅基混合波导中高相干、倍频程超连续谱(SC)产生及其在全光量化与编码方面的应用对片上光通信和全光信号处理等领域的发展具有重要意义。本项目一方面利用设计和制备的硅基混合波导产生了高相干、倍频程SC，利用其实现了高性能全光量化与编码；另一方面开展了硅基混合波导∕光子晶体光纤(PCF)非线性及器件应用研究。. 主要研究成果：(1)研究了非瞬时非线性多模PCF中模间同步效应；(2)研究了级联硅波导中抛物线脉冲(PP)产生和压缩，将高斯脉冲先转化成PP，再压缩至35.6fs；(3)利用CS2芯PCF获得了温度可控、高相干、倍频程SC；(4)设计了绝热悬壁梁式锥形硅波导，实现了飞秒脉冲的高效频谱压缩；(5)利用弯曲硫族化物波导中的频谱压缩和孤子自频移，实现了有效量化分辨率4bit的全光量化；(6)设计了多模硫族化物波导，利用不同模式产生了高相干、倍频程SC和频率梳；(7)利用设计的锥形硅纳米线实现了多波长PP无源产生；(8)设计了脊型悬臂梁式硫族化物波导，产生了高相干、多倍频程(1.76－14.42μm)SC和频率梳；(9)设计了CS2芯保偏PCF，在x和y偏振方向产生SC的范围为1.36－2.24μm和1.13－2.71μm；(10)设计了三个零色散波长的反脊型铝镓砷波导，获得了高相干、大于2.7个倍频程(2.2－14.5μm)SC和频率梳；(11)设计了全正色散T型锗波导，产生了高相干、大于2.7个倍频程(1.85－9.98µm)SC和频率梳；(12)设计了硝基苯芯PCF，获得了高相干SC和频率梳；(13)设计了偏振不敏感铝镓砷波导，准TE和TM模式产生的SC能够很好地重叠，对应谱宽为2.17－8.53μm和2.23－8.61μm；(14)设计了四个零色散波长的碳化硅波导，获得了近红外SC(873－2444nm)和中红外SC(1349－4727nm)；(15)研究了锥形多模PCF中自相似脉冲压缩，当输入脉冲宽度>3.58ps时，三个模式可实现高效的自相似压缩，压缩偏差<5%。. 硅基混合波导非线性、PCF非线性、全光量化与编码方面的研究成果将丰富硅基混合波导∕PCF非线性的基础理论，为高相干、倍频程SC源实现及其在全光量化与编码方面的应用提供新方法和新途径，并将促进可集成光通信和全光信号处理技术与器件的发展。