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.
ABSTRACT
The field of integrated photonics has advanced rapidly due to wafer-scale fabrication, with integrated-photonics platforms and fabrication processes being demonstrated at both infrared and visible wavelengths. However, these demonstrations have primarily focused on fabrication processes on silicon substrates that result in rigid photonic wafers and chips, which limit the potential application spaces. There are many application areas that would benefit from mechanically-flexible integrated-photonics wafers, such as wearable healthcare monitors and pliable displays. Although there have been demonstrations of mechanically-flexible photonics fabrication, they have been limited to fabrication processes on the individual device or chip scale, which limits scalability. In this paper, we propose, develop, and experimentally characterize the first 300-mm wafer-scale platform and fabrication process that results in mechanically-flexible photonic wafers and chips. First, we develop and describe the 300-mm wafer-scale CMOS-compatible flexible platform and fabrication process. Next, we experimentally demonstrate key optical functionality at visible wavelengths, including chip coupling, waveguide routing, and passive devices. Then, we perform a bend-durability study to characterize the mechanical flexibility of the photonic chips, demonstrating bending a single chip 2000 times down to a bend diameter of 0.5 inch with no degradation in the optical performance. Finally, we experimentally characterize polarization-rotation effects induced by bending the flexible photonic chips. This work will enable the field of integrated photonics to advance into new application areas that require flexible photonic chips.
ABSTRACT
In this work, we design and experimentally demonstrate the first, to the best of our knowledge, integrated polarization splitters and rotators at blue wavelengths. We develop compact and efficient designs for both a polarization splitter and rotator at a 422-nm wavelength, an important laser-cooling transition for 88Sr+ ions. These devices are fabricated in a 200-mm wafer-scale process and experimentally demonstrated, resulting in a measured polarization-splitter transverse-electric thru-port coupling of 98.0% and transverse-magnetic tap-port coupling of 77.6% for a compact 16-µm-long device and a polarization-rotator conversion efficiency of 92.2% for a separate compact 111-µm-long device. This work paves the way for more sophisticated integrated control of trapped-ion and neutral-atom quantum systems.
ABSTRACT
In this Letter, we propose and experimentally demonstrate the first, to our knowledge, integrated liquid-crystal-based (LC-based) variable-tap devices for visible-light amplitude modulation. These devices leverage the birefringence of LC medium to actively tune the coupling coefficient between two waveguides. First, we develop the device structure, theory of operation, and design procedure. Next, we summarize the fabrication and LC packaging procedure for these devices. Finally, we experimentally demonstrate amplitude modulation with 15.4-dB tap-port extinction within ±3.1â V for a 14-µm-long device at a 637-nm operating wavelength. These small-form-factor variable-tap devices provide a compact and low-power solution to integrated visible-light amplitude modulation and will enable future high-density integrated visible-light systems.
ABSTRACT
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 ±3.4â 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 19â dB through a water-filled tank.
ABSTRACT
We consider the impact of intra-wafer systematic spatial variation, pattern density mismatch, and line edge roughness on splitter-tree-based integrated optical phased arrays. These variations can substantially affect the emitted beam profile in the array dimension. We study the effect on different architecture parameters, and the analysis is shown to be consistent with experimental results.
ABSTRACT
In this work, an integrated liquid-crystal-based phase modulator operating at visible wavelengths was developed and experimentally demonstrated. A visible-light silicon-nitride-based 300-mm-wafer foundry platform and a liquid-crystal integration process were developed to leverage the birefringence of liquid crystal to actively tune the effective index of a section of silicon-nitride waveguide and induce a phase shift over its length. The device was experimentally shown to achieve a 41π phase shift within 4.8â Vpp for a 500-µm-long modulator, which means that a 2π phase shifter would need to be only 24.4â µm long. This device is a compact and low-power solution to the challenge of integrated phase modulation in silicon nitride and paves the way for future low-power small-form-factor integrated systems at visible wavelengths.
