Barty Group graduate student researcher Trevor Reutershan and Professor Chris Barty presented at Nuclear Photonics 2023, held this year in Durham, North Carolina, home of the Durham Bulls! Seen here are Chris, Trevor, and Barty Group collaborator Dr. Michael Jentschel at a Durham Bulls baseball game. Nuclear Photonics is a biennial conference concerning the pursuit of nuclear science and applications with photons.

Professor Barty opened the conference with his talk “Ultrahigh Intensity Laser Capabilities (world survey).” In this presentation, he reviewed the ultrahigh intensity laser facilities around the world that are capable of pursuing nuclear photonics. Trevor gave the talk “2D and 3D Imaging by Nuclear Resonance Absorption/Fluorescence Using Extremely Brilliant Compton Sources.” This talk discussed how the narrowband nature of the absorption and emission of electromagnetic radiation by atomic nuclei can be used in conjunction with spectrally filtered light from Extremely Brilliant Compton Sources for imaging, with a particular emphasis on medical imaging.

Both Professor Barty and Trevor were coauthors of the talk “Combination of a Diffraction Based Ultra-Narrow Band Width Filter with a Laser Compton Photon Source,” presented by Dr. Michael Jentschel, which discussed an effort to create a flexible ultra-narrowband, high energy photon source by filtering a high a spectral density Laser Compton Source (LCS) with an ultra-high precision crystal diffractometer. The talk also discussed ways that a crystal diffractometer could be used to manipulate a high energy beam from an LCS.

Professor Chris Barty co-chaired OPIC 2023 (Optics & Photonics International Congress 2023) in Yokohama, Japan! OPIC is held every April in Yokohama, Japan to bring together researchers and developers from around the world to discuss the science and industry of optics and photonics. Seen here is Chris fulfilling one of his important duties as co-chair of the conference.

No, we didn’t attend a meeting about flying saucers! The Barty Group presented five posters and one talk at Ultrafast Optics XIII (UFO XIII), held this year in San Carlos de Bariloche, Argentina at the Llao Llao Hotel. This post’s image is the gorgeous view from the Llao Llao hotel. Ultrafast Optics is a conference that invites scientists from across the globe to present on the latest developments in ultrafast (few picosecond or shorter) pulses of light and their applications. The conference is held every other year, each time in a unique location.

Kyle Chesnut gave the talk “Spatially and Temporally Chirped Beams: The Single Aperture Path to Exawatt Peak-Power Lasers,” discussing a path to exawatt scale lasers via chirped pulse juxtaposed with beam amplification (CPJBA). Kyle also authored the poster “Amplitude Neutral Temporal Electric-field Autocorrelator with Exquisite Resolution (ANTEATER)“, which was co-authored and presented by Haytham Effarah. This poster presented a novel amplitude balanced and dispersion compensated interferometric autocorrelator, used to measure the durations of ultrafast light pulses, that was designed and built in the Barty Lab.

Trevor Reutershan presented the poster “Path to 100 fs multi-MeV gamma rays from extremely brilliant Compton sources,” which is about how Extremely Brilliant Compton Scattering can be used to generate sub-100 fs, MeV scale pulses of light. Michael Seggebruch presented the posters “Shorter Duration Ultrafast Electro-optic Frequency Combs via Multi-Wavelength Seeding” and “Synthesis of Multi-GHz Ultrafast Pulse Trains via Harmonic Bandwidth Broadening of Electro-Optic Frequency Combs,” both of which present methods for generating shorter duration pulses from Multi-GHz electro-optic frequency combs. Eric Nelson presented the poster “Space-Time Correlated Foci of Exotic Spatially Chirped Femtosecond Beams,” which discusses the foci of exotic spatially chirped beams and their practical implementations.

Barty Group graduate student Trevor Reutershan presented his poster, coauthored with graduate student Haytham Effarah and Professor Chris Barty, on ‘Bayesian optimization of laser-Compton x-ray sources for medical imaging applications’ at the SPIE Medical Imaging Conference held in San Diego, CA. His work explored numerical models to help sample beam parameter spaces to find the best combination for medical imaging with laser-Compton scattering (LCS) sources. This work is fundamental to the Barty Group’s upcoming manuscript on scanning K-edge subtraction imaging using LCS sources.

Great work Trevor!

In a peer reviewed article published in Optics Express, graduate student researcher Kyle Chesnut and Professor Chris Barty presented a novel way of achieving exawatt-scale (1E18 Watts) laser pulses, i.e. pulses with up to 2 orders of magnitude higher peak power than generally available today.

High peak power laser pulses are typically created via chirped pulse amplification (CPA), where a low-energy, short-duration pulse is dispersed, or “stretched,” in time.  The resulting long duration, chirped pulse enables efficient energy extraction from solid state laser amplifiers without damage. After amplification the “chirp” on the pulse is removed with a parallel grating pair compressor and in doing so produces a high-energy, short-duration, high-peak-power pulse. CPA has been used to create petawatt-class (1E15 Watts) pulses at many labs around the globe. Professors Gerard Mourou and Donna Strickland were recipients of the 2018 Nobel Prize in Physics for developing CPA. It is possible to amplify a pulse to even higher energies than is allowed with chirped pulse amplification if the pulse is chirped in both space and time (both transverse and parallel to the direction of the beam’s propagation) (US680405B2). In their paper titled “Ideal spatio-temporal pulse distribution for exawatt-scale lasers based on simultaneous chirped beam and chirped pulse amplification,” Kyle and Chris presented the ideal 20 ns, spatio-temporally chirped pulse that would enable amplification to 25 kJ in a 40cmx40cm, Nd:Mixed-glass laser system. They further showed that this pulse could be compressed to ~100 fs using a novel six grating compressor arrangement, and in doing so could yield a laser pulse with a record breaking peak power of >0.2 exawatts!

Or at least it sure looks that way with this view from our offices on the second floor of Beall Applied Innovation!

Barty Lab graduate students, Leslie Heid and Michael Seggebruch, were volunteers at the 23rd annual Jet Propulsion Laboratory (JPL) Invention Challenge! This year, the challenge was to make the fastest device to direct five balls through variously placed wickets. Middleschool through JPL scientist teams built incredible machines that aimed, whacked, dropped, and launched balls using lasers, roombas, triggered hammers, rotary motors, solenoids, and pneumatic devices. Leslie and Michael spent the day right in the middle of the action (Inside the competition ring!) chasing balls. It was a great day that ended with a neat tour of the JPL museum. Next year, Barty Lab plans to enter the contest with their own machine. Stay tuned!

On November 3rd, 2022, Professor Chris Barty gave an invited talk titled “Extremely Brilliant Compton Sources and Potential Applications” at the 26th International Conference on the Application of Accelerators in Research and Industry (CAARI) in Denton, Texas. In his talk, he discussed the activities at Lumitron Technologies in Irvine, California to create next generation extremely brilliant Compton sources (EBCSs) via novel Compton scattering architectures based on x-band linear accelerator and ultrahigh repetition rate laser technology. He proposed that compared to the latest generation of synchrotron radiation sources that operate with lower emittance electron beams, EBCSs are poised to create similar if not higher brilliance outputs but with compact footprints of only a few meters. He also discussed potential medical and industrial applications of EBCS technology.

Professor Barty is the Chief Technical Officer, a co-founder, and an Executive Director of Lumitron Technologies.

Barty Group graduate student researcher Kyle Chesnut won a Student Poster Award at the 9th International Conference on Ultrahigh Intensity Lasers (ICUIL 2022). He received the award for his poster titled ‘Multi-pass Regenerative Stretcher to Produce Simultaneously Spatially and Temporally Chirped Pulses.’ This poster details a stretcher design that could enable an Exawatt peak-power laser, which could produce record focused laser intensity that would open new avenues of QED research.

Way to go Kyle!

Barty Group graduate student researchers Eric Nelson and Kyle Chesnut traveled to Jeju Island in South Korea to present their research at the 9th International Conference on Ultrahigh Intensity Lasers (ICUIL 2022). Eric’s poster, ‘Foci of Petawatt Class Space-Time Entangled Beams’, (bottom) examined how Petawatt laser facilities can shape their beams to explore new parameter spaces in high-field science. Kyle’s talk titled ‘Review of Chirped Pulse Juxtaposed with Beam Amplification as a Route to Exawatt Peak-power Lasers’ covered the design work done to date of a potential Exawatt peak-power laser to produce record focused laser intensity that would open new avenues of QED research. Kyle’s two posters, ‘Analysis of Higher-Order Phase Distortions from a Six-Grating Chirped-Beam Compressor for Exawatt-class CPJBA’ and ‘Multi-pass Regenerative Stretcher to Produce Simultaneously Spatially and Temporally Chirped Pulses’, the latter of which won a Student Poster Award, explored the details of two sub-systems of this laser.