Broad wavelength generation and conversion with multi modal Four Wave Mixing in silicon waveguides
Broad wavelength generation and conversion with multi modal Four Wave Mixing in silicon waveguides
复制标题
通过硅波导中的多模四波混频实现宽波长生成和转换
DOI：
--
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Lorenzo Pavesi
中科院分区：
文献类型：
--
作者：
S. Signorini;M. Mancinelli;M. Bernard;M. Ghulinyan;G. Pucker;Lorenzo Pavesi
实现宽波长产生和转换的可能性在经典光学和量子光学中引起了极大的兴趣。随着集成的非线性硅光子学的引入，由于结合了硅的高非线性折射率和光子波导提供的高限制，这些任务变得更加可行。利用这个平台，已经研究了几种波长转换的解决方案，包括光学处理[1]和在中红外(MIR)[2]中的应用。还可以利用实现宽且可控的波长产生的可能性来基于单光子或相关光子对来创建光的量子态的集成来源[3]。产生和转换都可以通过四波混频(FWM)来完成。四波混频是一个非线性光学过程，在这个过程中，两个频率处的泵浦光子分别转换为频率处的信号光子和ω/处的闲置光子(与ωi/ωS)。在波长转换的特定情况下，FWM由与将被转换为空闲(信号)的波长的信号(空闲)相同波长的种子波激励。四波混频必须满足能量守恒，根据能量守恒关系ωP+ωP=ωS+ωi，其效率由位相匹配条件决定。后一种情况与四波混频过程中涉及的波之间的位相失配有关，即Δk=Kp+Kp−Ks−Ki，其中Kp，Ks，Ki分别是泵浦、信号和闲置的波矢。当Δk=0时，满足相位匹配条件，使四波混频的效率最大化。对于波长产生和转换来说，重要的是相位匹配条件的光谱位置，它决定了实现转换或产生过程的最大效率的波长。正因为如此，控制相位匹配条件的技术已经被开发出来，重点在于通过适当的设计波导几何结构来定制群速度色散(GVD)的可能性[5]。虽然这些技术只考虑了一阶波导模，但这里我们建议利用在多模波导中传播的高阶模。高阶模的色散可以用来调节四波混频过程中相位匹配条件的光谱位置，在受激四波混频(SFWM)和自发四波混频(SFWM)中都实现了可控的大光谱平移。
The possibility to perform broad wavelength generation and conversion is of great interest in classical and quantum optics. With the introduction of integrated nonlinear silicon photonics, these tasks have been made even more viable thanks to the combination of the high nonlinear refractive index of silicon with the high confinement provided by the photonic waveguides. Exploiting this platform, several solutions for wavelength conversion have been investigated, for both optical processing [1] and applications in the Mid Infrared (MIR) [2]. The possibility to perform broad and controllable wavelength generation can be exploited also for creating integrated sources of quantum states of light based on single photons [3] or correlated photon pairs [4]. Both the generation and conversion can be accomplished by means of Four Wave Mixing (FWM). FWM is a nonlinear optical process in which two pump photons at frequency are converted into signal and idler photons at frequencies and ω/ respectively (with ωI/ωS). In the particular case of wavelength conversion, FWM is stimulated by a seed wave at the same wavelength of the signal (idler) that will be converted to the wavelength of the idler (signal). FWM has to satisfy the energy conservation, according to which the relation ωP + ωP = ωS + ωI holds, and its efficiency is ruled by the phase matching condition. This latter condition is related to the phase mismatch among the waves involved in the FWM process, that is evaluated as Δk = kp+ kp−kS−kI, where kP, kS, kI are the wavevectors for the pump, the signal and the idler, respectively. When Δk = 0, the phase matching condition is fulfilled and the efficiency of FWM is maximized. What is important for wavelength generation and conversion is the spectral position of the phase matching condition, which determines the wavelength at which the maximum efficiency of the conversion or generation process is achieved. Because of this, techniques for the control of the phase matching condition have been developed, focusing on the possibility to tailor the Group Velocity Dispersion (GVD) through a proper engineering of the waveguide geometry [5]. While these techniques consider only the first order waveguide mode, here we propose to exploit the higher order modes propagating inside a multimode waveguide. The dispersion of the higher order modes can be used to tune the spectral position of the phase matching condition for the FWM process, achieving controllable and large spectral translation in both Stimulated Four Wave Mixing (sFWM) and Spontaneous Four Wave Mixing (SFWM).