MRI: Development of Ultra-Broadband High-Power Frequency Comb Light Source for Advanced Spectroscopy and Imaging

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

General Audience Abstract: With support from the Physics Division, three programs in the Chemistry Division (CRIF, CMI, CSDM-A), the Astronomy Division, the Division of Materials Research, and the Office of Integrative Activities, Professors Allison and Liu at Stony Brook University will develop a new laser-based light source spanning a wide swath of the electromagnetic spectrum. The research will advance the state of the art in frequency comb technology and enable a variety of experiments involving 10 principal investigators (PIs) at Stony Brook along with a regional network of PIs from other nearby institutions. A frequency comb is a synthesizer for light waves, with which the user can control the electric field of light waves with the same precision routinely accomplished for radio frequency and microwave fields using the electronic technology that is the backbone of modern life. This control over light waves can enable myriad applications, however many applications of frequency combs have been limited by the available power and spectral coverage from currently available light sources. The new light source to be developed at Stony Brook will address this challenge by using high-power fiber lasers and nonlinear optics to generate frequency combs with unprecedented brightness and spectral coverage. With frequency combs spanning from the far-infrared to the soft x-ray, it is planned to cover more than 17 octaves (or about 2 and a half pianos’ worth) of frequency space. After development, the light source will be applied to experiments in four targeted areas: 1) nanometer resolved characterization of quantum materials and devices, 2) time-resolved imaging of electron motion in molecules and quantum materials, 3) ultrasensitive gas-phase molecular spectroscopy for both fundamental studies and analytical chemistry, and 4) quantum information science using atomic, molecular, and optical physics (AMO) platforms. It is also expected that the research will have a much broader impact than these activities at Stony Brook via the dissemination of detailed construction plans for the light source to the broader community, the training of students and postdocs in advanced optical methods, the development of new pedagogical experiments for undergraduate education, and potential future integration of the developed frequency comb technology into the NSF NeXUS, NSF’s new flagship laser-based user facility for ultrafast science. Technical Audience Abstract: PIs Allison and Liu will develop a new frequency comb light source at Stony Brook University with output spanning a wide swath of the electromagnetic spectrum, from the THz region (E < 0.001 eV) all the way to the soft x-ray (E > 200 eV). Built with a robust and reliable fiber-laser backbone, this light source will provide phase-coherent femtosecond-duration light pulses at MHz repetition rates that will be used in a variety of experiments. The light source development work proposed here will quantitatively advance the state of the art in frequency combs, and ultrafast optics in general, in a number of important ways. For one example, the PIs will produce the brightest source of broadband coherent THz and far-infrared radiation, orders of magnitude brighter than dedicated infrared/THz beamlines at synchrotron light sources. Similar to previous advances in light source technology, these developments will have a large qualitative impact on a wide range of science, with many applications both foreseen and unforeseen. At Stony Brook, the light source will specifically impact four activities, undertaken by 13 additional major users in collaboration with the PIs: 1) scanning near-field optical microscopy (SNOM) of quantum materials, 2) time- and angle-resolved photoemission (tr-ARPES) of quantum materials and molecular systems, 3) high-resolution and ultrafast spectroscopy of gas-phase molecules, and 4) laser stabilization in atomic, molecular, and optical (AMO) physics labs. Technology transfer to the broader community will be accomplished via detailed “how-to” papers, with complete parts lists, that enable others to build their own combs, and also via collaboration with the NSF NeXUS facility, NSF’s new flagship user facility for ultrafast spectroscopy. At Stony Brook, the new frequency comb system will also enable new experiments in the Laser Teaching Center, a unique facility at Stony Brook with full-time staff dedicated to education, outreach, and training. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.