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Abstract We report a novel approach for realizing tunable/reconfigurable terahertz (THz) mesh filters on the basis of micromachined mesa‐array structures. In this approach, different filter patterns are generated virtually using photogenerated free carriers in a semiconducting mesa‐array structure to achieve superior tunability and reconfigurability. Micromachined mesa‐array structures enable the formation of high fidelity, optically generated mesh filter structures for THz frequencies. To evaluate the proposed filter designs, the optically patterned spatial modulation properties of mesa‐array structures were first evaluated. Reconfigurable mesh filter prototypes were then designed and simulated using silicon mesa arrays with 50 × 50 μm2square mesa unit cells. Simulations show that reconfigurable bandpass filters (BPFs) operating in the frequency range of 108–489 GHz with insertion losses of 0.82–1.13 dB can be achieved. By employing smaller unit cells, the frequency tuning range and filtering performance can be further improved. In addition to BPFs, other filter functionalities can also be realized utilizing the proposed approach. The wide tuning range and reconfigurability of the mesh filters demonstrate that the proposed approach is promising for developing tunable/reconfigurable circuits and components for advanced THz sensing, imaging, and communications.
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Advanced photo-induced substrate-integrated waveguides using pillar-array structures for tunable and reconfigurable THz circuits
Substrate-integrated waveguides (SIWs) have recently attracted increasing attention for the development of terahertz (THz) circuits and systems. However, conventional SIWs employ fixed metallic vias to form the waveguide sidewalls, resulting in limited tunability and reconfigurability. In this paper, we report a novel approach for the realization of high-performance tunable and/or reconfigurable THz SIW structures. In this approach, photo-induced free carriers are generated in a high-resistivity silicon pillar-array structure to form well-defined, highly conductive, vertical sidewalls. The wave propagation properties of these optically-defined photo-induced SIWs (PI-SIWs) have been evaluated using full-wave electromagnetic simulations. Higher-functionality THz components, including a single-pole double-throw switch and a phase shifter were also designed and simulated. Based on these example circuits, PI-SIWs using pillar-array structures appear to be attractive candidates for the development of tunable and reconfigurable THz components for THz sensing, imaging, and communication systems.
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- PAR ID:
- 10136446
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 28
- Issue:
- 5
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 7259
- Size(s):
- Article No. 7259
- Sponsoring Org:
- National Science Foundation
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