Broadband terahertz near-field excitation and detection of silicon photonic crystal modes

Fuente: arXiv
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Main Authors: Lezhennikova, Kseniia, Mahmoodian, Sahand, Kuhlmey, Boris T., Abdeddaim, Redha, Enoch, Stefan, de Sterke, C. Martijn, Tuniz, Alessandro
Format: Preprint
Published: 2023
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author Lezhennikova, Kseniia
Mahmoodian, Sahand
Kuhlmey, Boris T.
Abdeddaim, Redha
Enoch, Stefan
de Sterke, C. Martijn
Tuniz, Alessandro
author_facet Lezhennikova, Kseniia
Mahmoodian, Sahand
Kuhlmey, Boris T.
Abdeddaim, Redha
Enoch, Stefan
de Sterke, C. Martijn
Tuniz, Alessandro
contents Chip-based terahertz (THz) devices are emerging as versatile tools for manipulating mm-wave frequencies in the context of integrated high-speed communication technologies for potential sixth-generation (6G) wireless applications. The characterization of THz devices is typically performed using far-field techniques that provide limited information about the underlying physical mechanisms producing them. As the library of chip-based functionalities expands, e.g., for tailoring the emission and directional propagation properties of THz antennas and waveguides, novel characterization techniques will likely be beneficial for observing subtle effects that are sensitive to a device's structural parameters. Here we present near-field measurements showing the emission properties of a broadband THz emitter placed in the vicinity of a photonic crystal (PHC) slab. These experiments reveal long-predicted emission properties, but which to our knowledge have yet to be experimentally observed at THz frequencies. We demonstrate three distinct effects between 0.3-0.5 THz: (i) field suppression at frequencies corresponding to quasi-TE bandgaps (ii) a frequency-dependent directed emission along two distinct pathways for two neighboring frequencies, resulting in a local field concentration; (iii) a re-direction of the emission, achieved by rotating the PHC with respect to the dipole orientation. Simulations reveal that the observed behavior can be predicted from the underlying band structure. Our results highlight the opportunities that PHCs can potentially provide for alignment-free, chip-based 6G technologies. Our experimental technique extends the applicability realms of THz spectroscopy and will find use for characterizing the THz modes supported by true samples, whose inherent imperfections cannot realistically be accounted for by simulations, particularly in highly dispersive frequency bands.
format Preprint
id arxiv_https___arxiv_org_abs_2310_01715
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Broadband terahertz near-field excitation and detection of silicon photonic crystal modes
Lezhennikova, Kseniia
Mahmoodian, Sahand
Kuhlmey, Boris T.
Abdeddaim, Redha
Enoch, Stefan
de Sterke, C. Martijn
Tuniz, Alessandro
Optics
Chip-based terahertz (THz) devices are emerging as versatile tools for manipulating mm-wave frequencies in the context of integrated high-speed communication technologies for potential sixth-generation (6G) wireless applications. The characterization of THz devices is typically performed using far-field techniques that provide limited information about the underlying physical mechanisms producing them. As the library of chip-based functionalities expands, e.g., for tailoring the emission and directional propagation properties of THz antennas and waveguides, novel characterization techniques will likely be beneficial for observing subtle effects that are sensitive to a device's structural parameters. Here we present near-field measurements showing the emission properties of a broadband THz emitter placed in the vicinity of a photonic crystal (PHC) slab. These experiments reveal long-predicted emission properties, but which to our knowledge have yet to be experimentally observed at THz frequencies. We demonstrate three distinct effects between 0.3-0.5 THz: (i) field suppression at frequencies corresponding to quasi-TE bandgaps (ii) a frequency-dependent directed emission along two distinct pathways for two neighboring frequencies, resulting in a local field concentration; (iii) a re-direction of the emission, achieved by rotating the PHC with respect to the dipole orientation. Simulations reveal that the observed behavior can be predicted from the underlying band structure. Our results highlight the opportunities that PHCs can potentially provide for alignment-free, chip-based 6G technologies. Our experimental technique extends the applicability realms of THz spectroscopy and will find use for characterizing the THz modes supported by true samples, whose inherent imperfections cannot realistically be accounted for by simulations, particularly in highly dispersive frequency bands.
title Broadband terahertz near-field excitation and detection of silicon photonic crystal modes
topic Optics
url https://arxiv.org/abs/2310.01715