An official website of the United States government
160×160 MEMS-Based 2-D Optical Phased Array
We present a two-dimensional ultra large aperture optical phase array (OPA) with 160×160 elements enabled with optical microelectromechanical system (MEMS). The random access beamsteering up to 4.4°×4.6° scanning range at 1550nm is demonstrated.
more »
« less
- Award ID(s):
- 1640329
- PAR ID:
- 10066725
- Date Published:
- Journal Name:
- Conference on Lasers and Electro-Optics
- Page Range / eLocation ID:
- SM3I.3
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
Continued integration of technologies capable of achieving higher degrees of sustainability while meeting global material and energy demands is of singular importance in halting human-caused climate change. Gas separation membranes composed of metal–organic frameworks (MOFs) are considered promising candidates for such integration; owing to their modular, scalable nature and high degree of tunability they are seen essential to maintain separation functionality. However, prior to sustainable implementation, both an evaluation of MOF characteristics and an intensive examination of MOF–gas molecule interactions are necessary to fully understand the fundamental separation criteria as well as to define suitable ranges of gas separation conditions. Herein, we present our findings on the greenhouse gas separation capabilities of the hydrophilic, Al-based MIL-160 in the selective uptake of carbon dioxide (CO 2 ) from other relevant greenhouse gases, i.e. , methane (CH 4 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), and nitric oxide (NO), including gravimetric solubility, permeability, and diffusivity calculations. We found that a MIL-160 membrane has excellent applicability in the separation of gases of varying electronegativities, with a diffusivity selectivity of 72.0, 9.53, and 13.8 for CH 4 , NO 2 , and NO, respectively, relative to CO 2 . Further, we demonstrate that the selectivity at which gas molecules diffuse through the MIL-160 membrane varies strongly with the simulation pressure, suggesting that such membrane system is potentially an ideal candidate for the development of pressure-swing adsorption processes that achieve gas separations efficiently while mitigating the emission of greenhouse gases.more » « less
-
An integrated frequency quadrupler operating at 160 GHz, producing 100 mW of output power, and achieving peak efficiency of 25.5% is described. The quadrupler design is based on prior art and consists of GaAs Schottky diodes with epitaxy transferred to a micromachined silicon carrier forming a heterogeneously-integrated chip. A newly-developed fabrication process that eliminates high temperature annealing and utilizes SU-8 for adhesive bonding was employed to realize the circuit. The new process improves device yield and reliability compared to previous implementations.more » « less
-
Soil hydraulic properties (SHP) are among the indicators of the diversity and health of an ecosystem and are commonly measured by two criteria: infiltration and water retention capacity. This may be seen as an “Ecological Alteration,” resulting from the sum biological and nonbiological processes which modify the structure of the soil, including bioturbation and the accumulation of organic matter. These changes in soil structure drive the changes in SHP. Central Chile has seen an abrupt and extensive land use/land cover transition from several hundred years of wheat cultivation (annually tilled) to short rotation (~25-30 yr) silviculture. This allows for neighboring assessment of soil impacts of transitioning from cultivated to uncultivated production as a function of time. Further, the region’s climate geography (a NorthSouth primary axis) allows us to view the soil health impacts of this change in planting along a precipitation gradient (850 – 1700 mm/yr) to help tease-out the impact of climate on temporal dynamics of soil properties. We measured infiltration in five recently transitioned first rotation locations along this precipitation gradient. Sampling plots were established for continuous wheat, early-, mid-, and late-stage pine plantations, and Chilean Native Forest. We sampled in both the dry summer months and again in the wet winter months. In the dry sampling period, we found transitions from wheat to silviculture saw an initial decrease in infiltration; however, over time (~30 years) infiltration in the plantations approached that of the Native Forest (increasing approximately by an order of magnitude in 30 years). In the wet sampling period, the results were more inconclusive. Some plots did not show an increase in infiltration capacity while others showed a gradual increase over the same 30-year period.more » « less
-
We report a novel ultra-thin metalens design based on photonic crystal slab (PCS) resonance modes. We experimentally verified with a metalens structure based on amorphous silicon on a quartz material platform by implementing the optical guided resonance on the PCS. The PCS metalens designs feature an ultra-thin device layer of about 160 nm at an operation wavelength of 940 nm. A full 2π transmission phase transition is realized by varying the air hole sizes at the design wavelength. Metalens devices with different phase change gradients were designed and fabricated to achieve different NAs. A maximum of 86.4% focusing efficiency is achieved. Imaging capabilities are characterized, and clear images are observed within the field of view. The PC resonance-based phase modulation design can be applied to optical beam manipulation, phase plate design, imaging, and laser beam formation applications.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1364/CLEO_SI.2018.SM3I.3
