Related Experiment Video
Updated: Dec 14, 2025
06:54
Photorealistic Learned Landscapes for Augmented Reality
Published on: June 27, 2025
568
Remote structuring of near-field landscapes
Vincent Ginis1,2, Marco Piccardo3,4, Michele Tamagnone3
1Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. ginis@seas.harvard.edu capasso@seas.harvard.edu.
Science (New York, N.Y.)
|July 25, 2020
Summary
Researchers developed a new theory for remote electromagnetic near-field shaping using cascaded mode conversion and interference. This allows for unprecedented control over near-field distributions for subwavelength applications.
Area of Science:
- Optics and Photonics
- Electromagnetism
- Nanotechnology
Background:
- The electromagnetic near field is crucial for subwavelength applications like microscopy and nanoparticle manipulation.
- Current methods for near-field structuring rely on local conversion of propagating waves using nanostructures.
Purpose of the Study:
- To develop a theory for remote shaping of the electromagnetic near field.
- To enable precise control over near-field distributions beyond conventional methods.
Main Methods:
- Developed a theory based on cascaded mode conversion and interference of counterpropagating guided waves.
- Utilized guided waves with different propagation constants for remote field structuring.
Main Results:
- Demonstrated the ability to control longitudinal and transverse variations of the near field at will.
- Achieved near-field distributions that deviate from the standard monotonic decay of evanescent fields.
- Experimental realization confirmed the theoretical predictions.
Conclusions:
- The developed theory provides a novel approach to remote near-field shaping.
- The method offers a pathway toward three-dimensional control of the near field for arbitrary polarization states and mode profiles.
- This opens new possibilities for advanced subwavelength applications.
Related Concept Videos
01:25Methods of Obtaining Topography
210
Topography involves measuring and mapping land elevations, natural features, and artificial structures to create accurate representations of the terrain. Topographic surveying relies on traditional and modern methods, each with distinct advantages and limitations.Traditional Surveying Methods:Transit stadia surveys and plane table surveys were widely used traditional surveying methods. These techniques relied on instruments like theodolites and stadia rods for measuring distances and angles,...
210
01:30Design Example: Identifying the Locations of Monuments in the Field Using Global Positioning System Device
296
Surveyors use Global Positioning System (GPS) technology to measure the precise location and elevation of points on Earth. In a recent survey, GPS receivers were used to determine the coordinates and elevations of two park monuments. The process involved careful mission planning, data collection, and correction to ensure accuracy. The survey began with mission planning to identify optimal satellite visibility and minimize Position Dilution of Precision (PDOP). A geodetic control point...
296
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
674
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
674
01:29Topographic Surveying and Contours
675
Topographic surveying is critical for documenting the Earth's surface, focusing on capturing elevations, slopes, and natural and man-made features. It is essential in construction planning, water resource management, and land-use analysis. The primary outcome of such surveys is a topographic map, which uses contour lines to visually represent the shape and slope of the terrain, providing valuable insights into the landscape's characteristics.Contour lines are fundamental to understanding the...
675
01:17Design Example: Alignment of a Road Line Using GIS
240
The alignment of a road line using Geographic Information Systems (GIS) is a critical process in civil engineering, combining advanced technology with practical decision-making. This methodology begins with the collection of geospatial data, including information on land cover, geomorphology, drainage patterns, slope, and contour details. Such data is typically acquired through satellite imagery and GIS tools, offering a comprehensive understanding of the terrain.Once the data is gathered, it...
240
01:19Design Example: Maintaining Level of an Embankment
311
Constructing a roadway embankment over uneven terrain requires precise leveling to ensure stability and proper drainage. Surveyors use a leveling instrument and staff to calculate ground elevations and determine the required fill material at each point along the embankment alignment.The process begins by positioning a leveling instrument near a benchmark with a known elevation. A backsight reading establishes the instrument height, which serves as a reference for subsequent measurements. A...
311