MacV: Miniaturised atomic clocks using VCSEL pump sources

MacV：使用 VCSEL 泵浦源的微型原子钟

• 批准号: EP/P034179/1
• 负责人: Peter Smowton
• 金额: $ 29.81万
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP034179%2F1
• 关键词: MacV; Miniaturised; atomic; clocks; using

Coherent population trapping (CPT) based miniature atomic clocks require low power, single mode laser diodes that can be directly modulated at a few gigahertz. Vertical Cavity Surface Emitting Lasers (VCSELs) are ideal for this application primarily due to their very low power consumption, wide wavelength tuning coefficient, reduced sensitivity to optical feedback, extended device lifetime, and small device footprint. Commercially available VCSELs have linewidths of ~50-100 MHz, and while this can be a problem for many other laser spectroscopy applications, it does not substantially compromise the quality of a CPT resonance. Conversely, due to the circular beam profile, VCSELs are particularly susceptible to polarisation instabilities; however, there are several novel design modifications that can be implemented to address this issue. Currently, there are no UK sources or any supply chain of reliable and robust VCSELs for miniature atomic clocks and a very limited number of commercial manufacturers globally developing VCSELs at the opimium wavelength for the application (Cs D1 - 894nm). Our project will establish a UK strategic capability focussed on the development and volume production of VCSEL laser sources, tailored specifically for to support the adoption of miniaturised atomic clock applications.This research team will focus on designing the epitaxial layers for operation at 894nm with maximum modulation speed, while maintaining a reasonable linewidth. It will contribute to the design of the fabricated structure to ensure a single polarisation.It will also contribute to the characterisation of chip scale prototypes and test structures for fast feedback to the epitaxial growth and for evaluation of the designed structures at the chip level.

基于相干布居俘获(CPT)的微型原子钟需要低功率的单模激光二极管，可以在几吉赫兹直接调制。垂直腔面发射激光器(VCSEL)是这种应用的理想选择，主要是因为它们的功耗非常低、波长调谐系数较宽、对光反馈的敏感度降低、延长了器件寿命以及器件占地面积小。商用VCSEL的线宽约为50-100 MHz，虽然这对许多其他激光光谱应用来说可能是一个问题，但它不会实质上影响CPT共振的质量。相反，由于圆形光束轮廓，VCSEL特别容易受到偏振不稳定性的影响；然而，有几种新的设计改进可以解决这个问题。目前，英国还没有可靠和坚固的微型原子钟VCSEL的来源或供应链，全球只有非常有限的商业制造商为应用开发鸦片波长的VCSEL(Csd1-894 nm)。我们的项目将建立英国的战略能力，专注于VCSEL激光光源的开发和批量生产，专门为支持微型原子钟应用而量身定做。该研究团队将专注于设计外延层，以最大调制速度运行在894 nm，同时保持合理的线宽。它将有助于制造结构的设计以确保单极化，还将有助于芯片规模原型和测试结构的表征，以便快速反馈到外延生长，并在芯片级评估所设计的结构。