Holographic concepts for analysing gain and refractive index dynamics in semiconductor lasers

用于分析半导体激光器增益和折射率动态的全息概念

• 批准号: 310973190
• 负责人: Professor Dr. Martin Hofmann
• 金额: --
• 依托单位: Lehrstuhl für Photonik und Terahertztechnologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/310973190?language=en
• 关键词: Holographic; concepts; analysing; gain; refractive

The goal of this research project is to develop and verify holographic concepts for simultaneous spatially and spectrally resolved analysis of the gain and refractive index dynamics in laterally multimode semiconductor lasers. For that purpose, we will continue to use holographic techniques. In the final step we aim to add a temporal resolution down to the picosecond range to the spectral and spatial resolution. In the first phase of this project, we could show that holographic concepts are well suited to analyze gain and refractive index dynamics in semiconductors with high precision. However, the results also provided unexpected problems for the analysis of laser diode devices which have to be solved first. These problems include the beam propagation through the waveguide of the diode, i.e. in- and outcoupling, an appropriate mode filtering, the exact determination of the input field, and providing a suitable reference for holographic measurements even under mechanical vibrations which are induced, for example, by the water cooling of semiconductor laser amplifiers. For these challenges we have developed appropriate solution concepts which shall be implemented in this continuation project. This includes modified in- and outcoupling optics with mode filters, concepts for determination of the optical input field into the diode, and a common path setup for a stable reference wave generation. Based on these improvements, we will set up an efficient, fast and in the first step stationary holographic characterization system for laser diodes that provides gain spectra, differential gain spectra, spectra for carrier induced refractive index changes, and spectra for the linewidth enhancement factor for the devices. This approach shall be implemented first for laterally single mode emitters and will then transferred to spatially extended emitters (broad area lasers, tapered amplifiers). In the last step, we will analyze how gain and refractive index dynamics can be determined time resolved by pulsed probe and reference fields. If this is possible, we aim to determine the best possible time resolution. The overall goal of this project is still to achieve with our holographic approaches a fundamental understanding of the gain and refractive index dynamics in semiconductor lasers. Based on that understanding we aim to find new approaches for an improvement of the device performance, for example concerning beam quality or short pulse generation.

该研究项目的目的是开发和验证全息概念，以对横向多模式半导体激光器中的增益和折射率动态进行简单和空间分析。为此，我们将继续使用全息技术。在最后一步中，我们旨在将临时分辨率向下添加到Picsecond范围内，并在光谱和空间分辨率上增加。在该项目的第一阶段中，我们可以证明全息概念非常适合分析具有高精度的半导体中的增益和屈光索引动力学。但是，结果还为分析激光二极管设备的分析提供了意外的问题，必须首先解决。这些问题包括通过二极管波导的横梁传播，即内置和远离耦合，适当的模式过滤，对输入场的确切确定，并为即使在机械振动下进行适当的参考，即使在机械振动下，这些振动即使是通过诸如半径激光仪的水冷却诱导的机械振动。对于这些挑战，我们已经开发了适当的解决方案概念，这些概念应在此继续项目中实施。这包括与模式过滤器的经过修改的内部和算法光学器件，用于确定二极管的光学输入字段的概念以及用于稳定参考波生成的常见路径设置。基于这些改进，我们将为激光二极管建立一个高效，快速和第一步的固定全息表征系统，该系统提供增益光谱，差异增益光谱，载波诱导的折射率变化的频谱以及线宽增强因子的线路谱系的光谱。该方法将首先用于侧面单模式发射器，然后将其转移到空间扩展的发射器（宽区域激光器，锥形放大器）。在最后一步中，我们将分析如何通过脉冲探针和参考字段来确定收益和折射率动力学的时间。如果可能的话，我们旨在确定最佳的时间分辨率。该项目的总体目标仍然是通过我们的全息方法对半导体激光器中的增益和屈光索引动力学的基本了解。基于这种理解，我们旨在找到改善设备性能的新方法，例如有关光束质量或短脉冲产生。