An official website of the United States government
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.
more »
« less
Visible-light uniform and unidirectional grating-based antennas for integrated optical phased arrays
Integrated optical phased arrays (OPAs) have emerged as a promising technology for various applications due to their ability to dynamically control free-space optical beams in a compact and non-mechanical manner. While integrated OPAs have traditionally focused on the infrared spectrum, advancements in visible-light integrated OPAs have been relatively limited despite their potential benefits for applications such as displays, 3D printing, trapped-ion quantum systems, underwater communications, and optogenetics. Moreover, integrated visible-light grating-based optical antennas, one of the crucial devices that forms a visible-light integrated OPA, have been relatively underexplored, especially for more advanced designs. In this paper, we address this gap by providing a thorough explanation of the design principles for integrated visible-light grating-based antennas and applying them to design and experimentally demonstrate five different antennas with varying advanced capabilities, including the first visible-light unidirectionally-emitting grating-based antennas for integrated OPAs. Specifically, we develop and experimentally demonstrate integrated visible-light exponentially-emitting single-layer, uniformly-emitting single-layer, exponentially-emitting dual-layer, uniformly-emitting dual-layer, and unidirectionally-emitting dual-layer grating-based antennas. This work aims to provide a thorough design guide for integrated visible-light grating-based antennas, facilitating future widespread use of integrated OPAs for new and emerging visible-light applications.
more »
« less
- Award ID(s):
- 2239525
- PAR ID:
- 10558924
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 32
- Issue:
- 26
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 46447
- Size(s):
- Article No. 46447
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
In this Letter, we present the first, to the best of our knowledge, liquid-crystal-based integrated optical phased arrays (OPAs) that enable visible-light beam forming and steering. A cascaded OPA architecture is developed and experimentally shown to emit a beam in the far field at a 632.8-nm wavelength with a power full width at half maximum of 0.4°×1.6° and 7.2° beam-steering range within ±3.4 V. Furthermore, we show the first visible-light integrated-OPA-based free-space-optical-communications transmitter and use it to demonstrate the first integrated-OPA-based underwater-wireless-optical-communications link. We experimentally demonstrate a 1-Gbps on–off-keying link through water and an electronically-switchable point-to-multipoint link with channel selectivity greater than 19 dB through a water-filled tank.more » « less
-
Density-based topology optimization is used to design large-scale, multi-layer grating couplers that comply with commercial foundry fabrication constraints while simultaneously providing beam profiles that efficiently couple to a single-mode optical fiber without additional optics. Specifically, we describe the design process and experimentally demonstrate both single- and dual-polarization grating couplers that couple at normal incidence (0° from the normal) with low backreflections (-13.7 dB and -15.4 dB at the center wavelength), broad 3 dB bandwidths (75 nm and 89 nm), and standard coupling efficiencies (-4.7 dB and -7.0 dB). The dual-polarization grating couplers exhibit over 30 dB of polarization extinction across the entire band. The devices were fabricated on the GlobalFoundries 45CLO CMOS platform and characterized across three separate wafers. This new design approach produces distinct features for multiple foundry layers and yields emitters with arbitrary, user-specified far-field profiles.more » « less
-
Abstract Imagine if it were possible to create 3D objects in the palm of your hand within seconds using only a single photonic chip. Although 3D printing has revolutionized the way we create in nearly every aspect of modern society, current 3D printers rely on large and complex mechanical systems to enable layer-by-layer addition of material. This limits print speed, resolution, portability, form factor, and material complexity. Although there have been recent efforts in developing novel photocuring-based 3D printers that utilize light to transform matter from liquid resins to solid objects using advanced methods, they remain reliant on bulky and complex mechanical systems. To address these limitations, we combine the fields of silicon photonics and photochemistry to propose the first chip-based 3D printer. The proposed system consists of only a single millimeter-scale photonic chip without any moving parts that emits reconfigurable visible-light holograms up into a simple stationary resin well to enable non-mechanical 3D printing. Furthermore, we experimentally demonstrate a stereolithography-inspired proof-of-concept version of the chip-based 3D printer using a visible-light beam-steering integrated optical phased array and visible-light-curable resin, showing 3D printing using a chip-based system for the first time. This work demonstrates the first steps towards a highly-compact, portable, and low-cost solution for the next generation of 3D printers.more » « less
-
We describe recent work towards a fully-integrated single-photon source based on the use of single atoms captured from a grating magneto-optical trap (GMOT). Single Rb atoms from a ber-coupled GMOT will be loaded into an optical dipole trap formed by light from an integrated polarization-maintaining (PM) ber. Trapped single atoms will be excited to the 2P1/2 state using resonant light. The resulting single-photon fluorescence will be collected through the same PM ber as is used for trapping, and routed to further experiments. We describe progress towards an intermediate imple- mentation incorporating integrated optical bers and free space light sources. The completed, fully-integrated single-photon source will have numerous applications in quantum communications and quantum information processing, and particularly in improvement of the performance of quantum key distribution systems.more » « less
