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Title: Phonon Polaritonics in Broad Terahertz Frequency Range with Quantum Paraelectric SrTiO 3
Abstract Photonics in the frequency range of 5–15 terahertz (THz) potentially open a new realm of quantum materials manipulation and biosensing. This range, sometimes called “the new terahertz gap”, is traditionally difficult to access due to prevalent phonon absorption bands in solids. Low‐loss phonon–polariton materials may realize sub‐wavelength, on‐chip photonic devices, but typically operate in mid‐infrared frequencies with narrow bandwidths and are difficult to manufacture on a large scale. Here, for the first time, quantum paraelectric SrTiO3enables broadband surface phonon–polaritonic devices in 7–13 THz. As a proof of concept, polarization‐independent field concentrators are designed and fabricated to locally enhance intense, multicycle THz pulses by a factor of 6 and increase the spectral intensity by over 90 times. The time‐resolved electric field inside the concentrators is experimentally measured by THz‐field‐induced second harmonic generation. Illuminated by a table‐top light source, the average field reaches 0.5 GV m−1over a large volume resolvable by far‐field optics. These results potentially enable scalable THz photonics with high breakdown fields made of various commercially available phonon–polariton crystals for studying driven phases in quantum materials and nonlinear molecular spectroscopy.  more » « less
Award ID(s):
2005096
PAR ID:
10525118
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
Wiley online library
Date Published:
Journal Name:
Advanced Materials
Volume:
35
Issue:
32
ISSN:
0935-9648
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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