Electro-optic quantum coherent interfaces map the amplitude and phase of a quantum signal directly to the phase or intensity of a probe beam. At terahertz frequencies, a fundamental challenge is not only to sense such weak signals (due to a weak coupling with a probe in the near-infrared) but also to resolve them in the time domain. Cavity confinement of both light fields can increase the interaction and achieve strong coupling. Using this approach, current realizations are limited to low microwave frequencies. Alternatively, in bulk crystals, electro-optic sampling was shown to reach quantum-level sensitivity of terahertz waves. Yet, the coupling strength was extremely weak. Here, we propose an on-chip architecture that concomitantly provides subcycle temporal resolution and an extreme sensitivity to sense terahertz intracavity fields below 20 V/m. We use guided femtosecond pulses in the near-infrared and a confinement of the terahertz wave to a volume of
We perform single-shot frequency domain holography to measure the ultrafast spatio-temporal phase change induced by the optical Kerr effect and plasma in flexible Corning Willow Glass during femtosecond laser–matter interactions. We measure the nonlinear index of refraction (
- Award ID(s):
- 1707237
- NSF-PAR ID:
- 10136366
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 45
- Issue:
- 5
- ISSN:
- 0146-9592; OPLEDP
- Page Range / eLocation ID:
- Article No. 1252
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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in combination with ultraperformant organic molecules ( ) and accomplish a record-high single-photon electro-optic coupling rate of , 10,000 times higher than in recent reports of sensing vacuum field fluctuations in bulk media. Via homodyne detection implemented directly on chip, the interaction results into an intensity modulation of the femtosecond pulses. The single-photon cooperativity is , and the multiphoton cooperativity is at room temperature. We show dynamic range in intensity at 500 ms integration under irradiation with a weak coherent terahertz field. Similar devices could be employed in future measurements of quantum states in the terahertz at the standard quantum limit, or for entanglement of subsystems on subcycle temporal scales, such as terahertz and near-infrared quantum bits. -
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