High-powEr phosphorous-based DFB Lasers for Cold ATom Systems (HELCATS)

越来越需要用于量子时钟应用的定制光源，以推动其尺寸、重量和成本的降低。特别是，我们的项目集中在Sr+时钟的来源上，这是正在开发的最有前途的离子系统之一，它提供了大约10^18水平的时钟精度，稳定性约为10^15/tau 1/2。该系统需要在~680-710 nm波长范围内的4个激光源。在这些波长发射的商业可用的激光器要么不满足严格的要求，锶+时钟系统或遭受的可靠性差，因为含铝的增益region.This项目开发的GaAs衬底上的磷基DFB激光器，以满足这一不断增长的需求。我们的创新在于利用合适的半导体材料（InGaAsP/AlInGaP），可以覆盖所需的光谱波段（680- 710 nm）。这种方法改善了与现有铝合金方法相关的可靠性和输出功率问题。此外，我们采用低损耗波导方法，以实现更窄的发射线宽和光子集成元件，以实现单独的DFB和放大器元件的片上制造。该联盟提供了一个制造供应链，从新外延层结构的生长和制造工艺的开发，到用于操作时钟系统的DFB激光器的晶圆级制造。该项目将在680至710 nm波长范围内工作的稳定DFB激光器的技术准备水平提高到后期商业前水平，即TRL>6。

There is a growing need for custom light sources for applications in quantum clocks in order to drive their reduction in size, weight, and cost. In particular, our project concentrates on sources for the Sr+ clock, one of the most promising ion systems being developed, which offers a clock accuracy around the 10^18 level, and stability at ~10^15/tau1/2. This system requires 4 laser sources in the ~680-710 nm wavelength range. The commercially available lasers emitting in these wavelengths either do not meet the stringent requirements for Sr+ clock systems or suffer from poor reliability because of the aluminium-containing gain region.This project develops phosphorous-based DFB lasers on GaAs substrates to address this growing need. Our innovation lies in utilising suitable semiconductor materials (InGaAsP/AlInGaP) that allows coverage of the required spectral bands (680-710nm). This approach ameliorates reliability and output power issues associated with the incumbent aluminium alloy approach. Furthermore, we adopt a low loss waveguide approach to enable narrower emission linewidths and elements of photonic integration to enable on-chip manufacturing of separate DFB and amplifier elements.The consortium provides a manufacturing supply chain from the growth of new epilayer structures and development of fabrication processes through to wafer scale manufacturing of DFB lasers to be deployed in operational clock systems. The project advances the Technological Readiness Level of stable DFB lasers operating in the 680 to 710 nm wavelength range to a late-stage pre-commercial level, i.e. TRL>6.