Modeling of quantum cascade laser frequency combs in the mid-infrared and terahertz spectral region

中红外和太赫兹光谱区量子级联激光频率梳的建模

基本信息

批准号：
323277022
负责人：
Professor Dr.-Ing. Christian Jirauschek
金额：
--
依托单位：
Professur für Computational Photonics
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/323277022?language=en
关键词：
Modeling quantum cascade laser frequency

项目摘要

In this research project, we focus on the modeling of quantum cascade laser (QCL) frequency combs in the mid-infrared (MIR) and terahertz (THz) regimes. The QCL is an extremely versatile light source, employing artificially engineered optical transitions in the conduction band of a semiconductor nanostructure rather than electron-hole recombination. In this way, frequency ranges are opened up which are otherwise inaccessible to compact semiconductor lasers. In addition, giant optical nonlinearities can be integrated into the QCL nanostructure, which has recently been exploited for the realization of compact MIR and THz frequency comb sources. These provide an equidistant line spectrum which serves as a ruler in the frequency domain, enabling many innovative applications in metrology and spectroscopy, e.g., in chemical sensing.To describe the underlying coherent nonlinear optical phenomena, we use the Maxwell-Bloch equations. In contrast to previously employed perturbative solutions, we envisage a fully time dependent numerical treatment. By coupling the resulting numerical scheme to ensemble Monte Carlo (EMC) carrier transport simulations, we obtain a self-consistent approach which does not require empirical input parameters. In this way, a quantitative numerical model including all relevant effects, such as four-wave mixing, dispersion and spatial hole burning, is obtained. Specifically, such a fully numerical approach not only provides an accurate description of frequency comb operation, but also allows us to identify the allowed parameter regime for the formation of stable combs and to investigate imperfect combs extending only over a fraction of the laser modes.In detail, the proposal involves the development of a stable and efficient numerical scheme for solving the Maxwell-Bloch equations, suitable for long-time simulations as required to eliminate transients. Building on this, a self-consistent modeling tool will be set up by coupling the scheme to EMC simulations. Furthermore, we will include resonant tunneling into our model, which plays an important role primarily in THz QCL structures and can significantly affect the spectral comb characteristics. In close collaboration with experimental groups, we will use the modeling tool for the analysis of QCL-based MIR and THz combs and the development of improved comb sources with, e.g., extended spectral bandwidth. A further goal is to theoretically assess the feasibility of broadband THz combs, e.g., obtained by down-conversion of MIR combs. This involves the development of a stable and efficient numerical approach for solving the Maxwell-Bloch equations without the commonly used rotating-wave approximation.

在该研究项目中，我们专注于中红外（MIR）和Terahertz（THZ）制度中量子级联激光（QCL）频率梳的建模。 QCL是一种非常通用的光源，在半导体纳米结构的传导带中使用人工设计的光学转换，而不是电子孔重组。这样，打开频率范围，这些范围是紧凑的半导体激光器无法访问的。此外，可以将巨大的光学非线性集成到QCL纳米结构中，该结构最近被利用以实现紧凑的miR和THZ频率梳源。这些提供了等距线频谱，该线光谱是频域中的标尺，从而实现了许多创新的计量和光谱应用，例如在化学传感中描述了基本的相干非线性光学现象，我们使用MaxWell-Blbloch方程。与先前使用的扰动溶液相反，我们设想了完全依赖时间的数值处理。通过将所得的数值方案耦合到集合Monte Carlo（EMC）载体传输模拟，我们获得了一种自洽的方法，不需要经验输入参数。通过这种方式，获得了一个定量数值模型，包括所有相关效应，例如四波混合，分散和空间孔燃烧。具体而言，这种完全数值的方法不仅提供了频率梳操作的准确描述，而且还允许我们识别稳定梳子形成的允许参数制度，并研究仅在激光模式的一小部分范围内延伸的不完美梳子。详细信息，该建议涉及开发稳定有效的数值方案，以解决Maxwell-Bloch方程，适用于消除瞬变的长期模拟。在此基础上，将通过将计划与EMC仿真相连，将建立一个自一致的建模工具。此外，我们将在模型中包括谐振隧道，该模型主要在THZ QCL结构中起重要作用，并且可以显着影响光谱梳子特征。在与实验组密切合作的情况下，我们将使用建模工具来分析基于QCL的MiR和THZ梳子，并使用例如扩展的光谱带宽来开发改进的梳子源。另一个目标是从理论上评估宽带Thz梳子的可行性，例如通过mir梳子的下调获得。这涉及开发稳定有效的数值方法，用于求解Maxwell-Bloch方程，而无需常用的旋转波近似。