A Space-Qualified Optical Frequency Comb with Integrated Nanophotonic Heterodyne Module

This Phase I NASA SBIR funding will be used to accelerate the development of a compact, space-qualified, octave-spanning optical frequency comb (OFC), an essential component of next-generation optical atomic clocks. The deployment of optical clocks to space carries far-reaching implications for deep-space travel, global navigation, and precision timing. However, current state of the art OFC designs are not space-qualified due to limitations in size, weight, and power (SWaP) and environmental (vibration and radiation). We will develop a low SWaP, space-qualified OFC system with multi-octave spectral coverage, enabling self-referencing and coverage of relevant atomic transitions for Yb and Sr optical atomic clocks. Our design, based on robust packaging and the replacement of bulky, radiation sensitive components with integrated nanophotonics, will lead to dramatic reduction in SWaP, and to the level of robustness necessary for long-term space travel. Our compact, low-SWaP frequency comb will have a broad impact in both space and non-space based applications. In particular, atomic clocks and (ion/atom-based) quantum computing both require the simultaneous referencing and stabilization of different wavelength lasers, and thus stand to benefit enormously from a low-SWaP, multi-octave-spanning OFC design. We are well-positioned both professionally and geographically to capitalize on this opportunity - the Chi3 Optics team has decades of experience in OFC/nonlinear optics, and is located in Boulder, CO, in close proximity to industry and academic leaders in atomic clocks and quantum computing. We thus expect that this project will naturally drive advancement in the development of these essential technologies.
Benefits: Our space-qualified optical frequency comb will catalyze the deployment of miniaturized optical atomic clocks, holding enormous promise in advancing a variety of space-based applications, for example by improving deep space navigation by enabling more precise and efficient tracking of space probes, and improving the capabilities of satellite positioning systems. The multi-octave spectrum produced by our space-qualified comb will cover the relevant optical transitions for ytterbium and strontium, the most relevant candidates for optical atomic clocks. Furthermore, the unique radiation-resistant, low-SWaP design based on integrated photonics will naturally enable the stabilization of on-chip clock and cooling lasers necessary. In this way, our innovation will enable the extraordinary precision of optical atomic clocks to be deployed and maintained for long-term space and orbital missions. The development of this compact and robust broadband frequency comb system will have a broad impact beyond purely space-based applications. For example, several of the most promising platforms for scalable quantum computing, an essential next-gen technology with far-reaching national security implications, require the use of lasers targeting various electronic transitions for cooling, readout, and logic operations. Our chip-based broadband frequency comb is the ideal tool for the simultaneous stabilization of all these lasers, which span a large range of different wavelengths. With this miniature frequency comb, we can develop a portable dual-comb spectrometer, extending this technology to dual-comb spectroscopy. In the visible wavelength range, this approach enables the detection of certain toxic gases, with enhanced sensitivity reaching the parts-per-million (ppm) level. Another promising application of this technology is human breath analysis with this chip-based dual comb spectroscopy, which could enable non-invasive detection of biomarkers for medical diagnostics.