Ralph Jimenez
JILA, a joint institute of the University of Colorado Boulder and the National Institute of Standards and Technology (NIST) hosted its inaugural workshop on recent technological and research advancements in quantum light from July 17 to 19, 2024. The conference was sponsored by the National Science Foundation (NSF)-funded JILA Physics Frontier Center (PFC), the CUbit Quantum Initiative, and laser company Toptica.
The event invited speakers from various prestigious institutions, including Texas A&M University, the National Autonomous University of Mexico, Columbia University, Wake Forest University, Livermore National Lab, the University of Illinois Urbana-Champaign, Caltech, Oak Ridge National Lab, Cornell University, William & Mary, University College London, the University of Oregon, the University of Toronto, and the University of Virginia, along with multiple representatives from NIST.
In a new paper published in the Journal of Physical Chemistry Letters, Jimenez and his team report a new experimental setup to search for the cause of a mysterious fluorescent signal that appears to be from entangled photon excitation. The results of their new experiments suggested that hot-band absorption (HBA) by the subject molecules, could be the potential culprit for this mysterious fluorescent signal, making it the prime suspect.
Most researchers would agree that it is much easier to write a paperabout an observed effect than a paper proving the nonexistence of the effect when it is not observed. NIST JILA Fellow Ralph Jimenez found this to be the casein contributing to a recent paper published in Physical Review Applied. The authors of this paper were originally hoping to observe the increased efficiency in two-photon absorption, a special type of process used in microscopy of living tissue, that had been reported by other research labs. This increased efficiency would be determined by an additional absorption signal than the one being produced by classical light. This additional signal came from using entangled photons. Instead, Jimenez and his team of collaborators from NIST found no additional signal in their measurements, indicating a lack of absorption entirely from the entangled photons.
Fluorescence and dyes are great tools to study cells, proteins, bacteria, or DNA. But scientists need to efficiently sort out the glowing material from the non-glowing stuff in their samples. The Jimenez Lab and the JILA Electronics Shop teamed up to create an improved flow cytometry system which can not only sort fluorescent material faster, it can sort by fluorescence lifetime and brightness faster than a commercially available system.
The actors are molecules. The plot, broken molecular bonds. JILA Fellow Ralph Jimenez and a team of detector experts at the National Institute of Standards and Technology (NIST) are working together to make X-ray movies of a molecular drama. The team at NIST built a microcalorimeter X-ray spectrometer capable of performing time-resolved spectroscopy; in other words: a camera to film molecules. They use this camera to learn how molecules break their bonds –do the electrons rearrange, do the other atoms quake?
JILA Fellow and NIST Physicist Ralph Jimenez received the 2017 Arthur S. Flemming Award for outstanding public service as a Federal employee. Jimenez was one of 12 honorees across all parts of the Federal government to receive the Flemming Award this cycle. Jimenez was a winner in the Applied Science and Engineering category for hispioneering researchon combining microfluidics, ultrafast lasers, biochemistry and molecular biology to dramatically accelerate the creation and characterization of specialized biomolecules to serve as sensors within living cells.
Ralph Jimenez received a Department of Commerce Bronze Medal for Superior Federal Service at a ceremony held in mid-December 2016. The Medal is the highest honor presented by the National Institute of Standards and Technology (NIST). Under Secretary of Commerce for Standards and Technology and NIST Director Willie E. May presided over the awards ceremony, which was held concurrently at NIST's Gaithersburg, Maryland, and Boulder, Colorado, campuses.
Far-red fluorescent light emitted from proteins could one day illuminate the inner workings of life. But before that happens, scientists like Fellow Ralph Jimenez must figure out how fluorescent proteins’ light-emitting structures work. As part of this effort, Jimenez wants to answer a simple question: How do we design red fluorescent proteins to emit longer-wavelength, or redder, light?
Because red fluorescent proteins are important tools for cellular imaging, the Jimenez group is working to improve them to further biophysics research. The group’s quest for a better red-fluorescent protein began with a computer simulation of a protein called mCherry that fluoresces red light after laser illumination. The simulation identified a floppy (i.e., less stable) portion of the protein “barrel” enclosing the red-light emitting compound, or chromophore. The thought was that when the barrel flopped open, it would allow oxygen in to degrade the chromophore, thus destroying its ability to fluoresce.