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Highlights and Latest News

Congratulations to Ryan Kowalski for the VINSE spotlight publication!

Nov. 28, 2022—“Mid- to Far-Infrared Anisotropic Dielectric Function of HfS2 and HfSe2” published in Advanced Optical Materials, selected as a VINSE Spotlight Publication.   About the author: Ryan Kowalski is a fourth-year graduate student pursuing a PhD in Interdisciplinary Materials Science under the direction Dr. Josh Caldwell. Using infrared spectroscopy, the Caldwell group investigates the optical properties of...

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The group participated in VINSE NanoDay!

Nov. 7, 2022—Last week, the group participated in the 22nd Annual Nanoscience & Nanotechnology Forum NanoDay, which featured a keynote from Prof. Dmitri Basov. In the afternoon, Josh gave a talk about “Exploring the Role of Anisotropy and Strong Coupling in Driving Infrared Nanophotonics”. All the group members presented posters during the NanoDay poster competition, including two first-year...

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Check out our new collaborative work with Justus Ndukaife’s group!

Oct. 12, 2022—Our recent collaborative work with Justus Ndukaife’s  group demonstrates a novel approach to engineering quasi-bound states in the continuum (quasi-BIC) by introducing slots into a zigzag array of elliptical silicon resonators. The electric field intensity enhancement near the apex and the quality factor of the quasi-BIC resonance are both increased. The demonstration holds enormous potential in partial trapping, sensing,...

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Check out Ryan Kowalski and Ryan Nolen’s paper on the infrared dielectric function of Hf-based TMDs!

Sep. 7, 2022—Our recent work on the infrared dielectric function of Hf-based transition metal dichalcogenides (TMDs) was just published in Advanced Optical Materials! In this work, we extract the mid- to far-infrared dielectric function of HfS2 and HfSe2, which have exceptionally large Reststrahlen bands that extend throughout the far-infrared. In collaboration with the Stephanie Law’s group (U...

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The Caldwell and Landman groups were awarded the Chancellor’s Award for Research!

Sep. 2, 2022—The Caldwell and Landman groups were awarded the Chancellor’s Award for Research at Vanderbilt! This is a unique honor that can only be received by a faculty member once and highlights the overall research from the group and the impact of a specific publication. Here, this was led by graduate student Mingze He of the...

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Our summer students won REU poster awards!

Aug. 4, 2022—Congratulations to our summer students Thiago for winning the best layout award and Levi for winning the best poster award! And thanks to Thiago and Levi for all the hard work they put in this summer.

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Check out Ryan Nolen’s paper on engineering the dispersion of surface plasmon polariton/epsilon-near-zero modes!

Aug. 2, 2022—Check out our recent work from Ryan Nolen and our collaborators, which is just published today on Advanced Photonics Research! Ryan and coworkers studied the hybridized dispersion of surface plasmon polariton (SPP) and epsilon-near-zero (ENZ) modes within multilayer doped cadmium oxide (CdO) structures featuring dielectric CdO coating or spacer layer. This work demonstrated the simultaneous control over the SPP-ENZ...

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We attended the Gordon conference on plasmonics and nanophotonics!

Aug. 2, 2022—The group attended Gordon Research Conference (GRC) and the associated Gordon Research Seminar (GRS) on plasmonics and nanophotonics last month. Guanyu led the discussion on GRS “Enhancing Light-Matter Interactions with Metamaterials, Metasurfaces and Nanoparticles”, which features Joseph’s talk on shear polaritons in bGO. Guanyu gave a poster presentation on his thermal emitter works using SiC...

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Joseph and Guanyu passed the qualifying exam!

Jun. 6, 2022—Joseph passed his qualifying exam in May just before our trip to Hawaii. The title of Joseph’s presentation is “optics and nanophotonics of phonons in anisotropic systems”. And Guanyu passed his qualifying exam on June 2nd. The title of Guanyu’s presentation is “strong coupling of phonon polaritons for engineering thermal emission and heat transfer”. Congratulations...

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We attended the MRS Spring Meeting in Hawaii!

May. 24, 2022—The group attended the Spring Meeting of the Materials Research Society in Hawaii. Josh organized the symposium on quantum materials: Light-Matter Strong Coupling in the Infrared and THz. Mingze discussed his work in Tamm plasmon, and Joseph presented his superlattice work. Guanyu also presented his recent SiC subarray work, which won the best poster award (see the picture...

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Congratulations to Ryan Kowalski for the NASA fellowship!

May. 24, 2022—The Caldwell lab’s proposal “Nano-Optic Probing of Vibrational Modes of Defects and Color Centers in Semiconductors”, authored by graduate student Ryan Kowalski, was selected by the NASA Space Technology Graduate Research Opportunity (NSTGRO) to research single-photon emitting point defects in hexagonal boron nitride and silicon carbide. The NSTGRO is part of NASA’s initiative to support...

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Check out our new collaborative work with Alexander Paarmann’s group!

Mar. 29, 2022—Our recent collaborative work with Alexander Paarmann’s group demonstrates super-resolution microscopy in the long-wave infrared (LWIR) range using IR-visible sum-frequency generation. The localized surface phonon polaritons in 4H-SiC nanostructures are imaged as a proof-of-concept. Check it out here!

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Our work discovering “Shear” polaritons was just published in Nature!

Mar. 17, 2022—Check out our recent work published in Nature! With collaborators we discovered new “shear” hyperbolic polaritons that arise from the asymmetry in monoclinic beta-Gallium Oxide. These unique polaritons show remarkable new physics, and offer huge promise in controlling light propagation at the nano-scale! Find the article here! And a press release here!

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Check out our Perspective paper on ACS Photonics!

Mar. 14, 2022—Take a look at the recent Perspective paper on ACS Photonics! We introduced the physics and theories of anisotropic polaritons, reviewed the recent progress, and moved on to a discussion of outstanding challenges and potentials in this field. This is a collaborative work with Prof. Thomas G. Folland at The University of Iowa, Jiahua Duan and Prof. Pablo...

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Highlighting our collaborative Nature paper on electron spectroscopy and imaging of interface phonons!

Feb. 21, 2022—Take a look at the recent work from Joseph Matson of the Interdisciplinary Materials Science at Vanderbilt University within the Josh Caldwell group (Vanderbilt University Mechanical Engineering) and Deliang Bao (包德亮) and Andrew O’Hara within the group of Sokrates Pantelides (Vanderbilt Physics) that was published today in Nature (Springer Nature Group). The work employed electron beam methods to directly image and measure vibrational modes at...

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