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Integrated optical phased arrays (OPAs) have enabled cutting-edge applications where optical beam steering can benefit from chip-scale integration. However, the majority of integrated OPA demonstrations to date have been limited to showing far-field beam forming and steering. There are, however, many emerging applications of integrated photonics where emission of focused light from a chip is desirable, such as in integrated optical tweezers for biophotonics, chip-based 3D printers, and trapped-ion quantum systems. To address this need, we have recently demonstrated the first near-field-focusing integrated OPAs; however, this preliminary demonstration was limited to emission at only one focal plane above the chip. In this paper, we show the first, to the best of our knowledge, spiral integrated OPAs, enabling emission of focusing beams with tunable variable focal heights for the first time. In the process, we develop the theory, explore the design parameters, and propose feed-structure architectures for such OPAs. Finally, we experimentally demonstrate an example spiral integrated OPA system fabricated in a standard silicon-photonics process, showing wavelength-tunable variable-focal-height focusing emission. This work introduces a first-of-its-kind integrated OPA architecture not previously explored or demonstrated in literature and, as such, enables new functionality for emerging applications of OPAs that require focusing operation.
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Large-scale MEMS-actuated 2-D optical phased arrays
Optical phased arrays (OPAs) are key enabling elements for solid-state LiDAR (light detection and ranging) and three-dimensional (3-D) imaging without bulk mechanical moving parts [1]. Solid state LiDARs are highly sought after for self-driving cars and autonomous vehicles [2,]. OPA's are also instrumental for free-space communications [3], optical switches [4], and holographic displays [5]. OPAs are capable of sophisticated beamforming such as scanning and simultaneous pointing/tracking of multiple objects. Narrow beam divergence and large field of views (FOVs) are desirable for these applications.
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- Award ID(s):
- 1640329
- PAR ID:
- 10066727
- Date Published:
- Journal Name:
- Micro Electro Mechanical Systems (MEMS)
- Page Range / eLocation ID:
- 21 to 24
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/MEMSYS.2018.8346471
