Time-refraction optics with single cycle modulation

Journal Article · 16 May 2023 · Nanophotonics (Online)

DOI: https://doi.org/10.1515/nanoph-2023-0126 · OSTI ID:1975911

Lustig, Eran ^[1]; Segal, Ohad ^[1]; Saha, Soham ^[2]; Bordo, Eliyahu ^[1]; Chowdhury, Sarah N. ^[2]; Sharabi, Yonatan ^[1]; Fleischer, Avner ^[3]; Boltasseva, Alexandra  ^[2]; Cohen, Oren ^[1]; Shalaev, Vladimir M. ^[2]; Segev, Mordechai  ^[1]

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1. Physics Department and Solid State Institute, Technion-Israel Institute of Technology , Haifa , Israel
2. School of Electrical and Computer Engineering, Birck Nanotechnology Center and Purdue Quantum Science and Engineering Institute, Purdue University , West Lafayette , IN , USA
3. School of Chemistry, Tel Aviv University , Tel Aviv , Israel

Abstract We present an experimental study of optical time-refraction caused by time-interfaces as short as a single optical cycle. Specifically, we study the propagation of a probe pulse through a sample undergoing a large refractive index change induced by an intense modulator pulse. In these systems, increasing the refractive index abruptly leads to time-refraction where the spectrum of all the waves propagating in the medium is red-shifted, and subsequently blue-shifted when the refractive index relaxes back to its original value. We observe these phenomena in the single-cycle regime. Moreover, by shortening the temporal width of the modulator to ∼5–6 fs, we observe that the rise time of the red-shift associated with time-refraction is proportionally shorter. The experiments are carried out in transparent conducting oxides acting as epsilon-near-zero materials. These observations raise multiple questions on the fundamental physics occurring within such ultrashort time frames, and open the way for experimenting with photonic time-crystals, generated by periodic ultrafast changes to the refractive index, in the near future.

• Research Organization: Purdue Univ., West Lafayette, IN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• Grant/Contract Number: SC0017717
• OSTI ID: 1975911
• Journal Information: Nanophotonics (Online), Journal Name: Nanophotonics (Online) Journal Issue: 12 Vol. 12; ISSN 2192-8614
• Publisher: Walter de Gruyter GmbHCopyright Statement
• Country of Publication: Germany
• Language: English