On-chip near-field THz imaging probe integrated with a detector

In this roadmap article, we have focused on the most recent advances in terahertz (THz) imaging with particular attention paid to the optimization and miniaturization of the THz imaging systems. Such systems entail enhanced functionality, reduced power consumption, and increased convenience, thus being geared toward the implementation of THz imaging systems in real operational conditions. The article will touch upon the advanced solid-state-based THz imaging systems, including room temperature THz sensors and arrays, as well as their on-chip integration with diffractive THz optical components. We will cover the current-state of compact room temperature THz emission sources, both optolectronic and electrically driven; particular emphasis is attributed to the beam-forming role in THz imaging, THz holography and spatial filtering, THz nano-imaging, and computational imaging. A number of advanced THz techniques, such as light-field THz imaging, homodyne spectroscopy, and phase sensitive spectrometry, THz modulated continuous wave imaging, room temperature THz frequency combs, and passive THz imaging, as well as the use of artificial intelligence in THz data processing and optics development, will be reviewed. This roadmap presents a structured snapshot of current advances in THz imaging as of 2021 and provides an opinion on contemporary scientific and technological challenges in this field, as well as extrapolations of possible further evolution in THz imaging.

Download Full-text

Demonstration of an integrated nanophotonic chip-scale alkali vapor magnetometer using inverse design

Light Science & Applications ◽

10.1038/s41377-021-00499-5 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Yoel Sebbag ◽

Eliran Talker ◽

Alex Naiman ◽

Yefim Barash ◽

Uriel Levy

Keyword(s):

Spatial Resolution ◽

Near Field ◽

Computer Assisted ◽

Experimental Characterization ◽

Optical Isolation ◽

New Concepts ◽

On Chip ◽

The Cost ◽

Micrometer Scale

AbstractRecently, there has been growing interest in the miniaturization and integration of atomic-based quantum technologies. In addition to the obvious advantages brought by such integration in facilitating mass production, reducing the footprint, and reducing the cost, the flexibility offered by on-chip integration enables the development of new concepts and capabilities. In particular, recent advanced techniques based on computer-assisted optimization algorithms enable the development of newly engineered photonic structures with unconventional functionalities. Taking this concept further, we hereby demonstrate the design, fabrication, and experimental characterization of an integrated nanophotonic-atomic chip magnetometer based on alkali vapor with a micrometer-scale spatial resolution and a magnetic sensitivity of 700 pT/√Hz. The presented platform paves the way for future applications using integrated photonic–atomic chips, including high-spatial-resolution magnetometry, near-field vectorial imaging, magnetically induced switching, and optical isolation.

Download Full-text

Near-field THz imaging of a split ring resonator matrix

2011 International Conference on Infrared, Millimeter, and Terahertz Waves ◽

10.1109/irmmw-thz.2011.6105043 ◽

2011 ◽

Author(s):

F. Blanchard ◽

A. Doi ◽

T. Tanaka ◽

H. Hirori ◽

J. Darmo ◽

...

Keyword(s):

Ring Resonator ◽

Near Field ◽

Split Ring Resonator ◽

Thz Imaging ◽

Split Ring

Download Full-text

Direct quantification of topological protection in symmetry-protected photonic edge states at telecom wavelengths

Light Science & Applications ◽

10.1038/s41377-020-00458-6 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Sonakshi Arora ◽

Thomas Bauer ◽

René Barczyk ◽

Ewold Verhagen ◽

L. Kuipers

Keyword(s):

Near Field ◽

Edge States ◽

Quantum Networks ◽

Hall Effects ◽

Upper Limits ◽

On Chip ◽

Symmetry Protected ◽

Topological Robustness ◽

Direct Quantification ◽

Sub Wavelength

AbstractTopological on-chip photonics based on tailored photonic crystals (PhCs) that emulate quantum valley-Hall effects has recently gained widespread interest owing to its promise of robust unidirectional transport of classical and quantum information. We present a direct quantitative evaluation of topological photonic edge eigenstates and their transport properties in the telecom wavelength range using phase-resolved near-field optical microscopy. Experimentally visualizing the detailed sub-wavelength structure of these modes propagating along the interface between two topologically non-trivial mirror-symmetric lattices allows us to map their dispersion relation and differentiate between the contributions of several higher-order Bloch harmonics. Selective probing of forward- and backward-propagating modes as defined by their phase velocities enables direct quantification of topological robustness. Studying near-field propagation in controlled defects allows us to extract upper limits of topological protection in on-chip photonic systems in comparison with conventional PhC waveguides. We find that protected edge states are two orders of magnitude more robust than modes of conventional PhC waveguides. This direct experimental quantification of topological robustness comprises a crucial step toward the application of topologically protected guiding in integrated photonics, allowing for unprecedented error-free photonic quantum networks.

Download Full-text