Conditions for designing single-mode air-core waveguides in three-dimensional photonic crystals

2006 ◽  
Vol 89 (16) ◽  
pp. 161103 ◽  
Author(s):  
Virginie Lousse ◽  
Jonghwa Shin ◽  
Shanhui Fan
2007 ◽  
Vol 15 (6) ◽  
pp. 3502 ◽  
Author(s):  
Gaoxin Qiu ◽  
Kevin Vynck ◽  
David Cassagne ◽  
Emmanuel Centeno

2002 ◽  
Vol 12 (12) ◽  
pp. 3637-3639 ◽  
Author(s):  
Yong-Hong Ye ◽  
Theresa S. Mayer ◽  
Iam-Choon Khoo ◽  
Ivan B. Divliansky ◽  
Neal Abrams ◽  
...  

2013 ◽  
Vol 21 (10) ◽  
pp. 12443 ◽  
Author(s):  
Jiapeng Fu ◽  
Aniwat Tandaechanurat ◽  
Satoshi Iwamoto ◽  
Yasuhiko Arakawa

Author(s):  
Ted Janssen ◽  
Gervais Chapuis ◽  
Marc de Boissieu

The law of rational indices to describe crystal faces was one of the most fundamental law of crystallography and is strongly linked to the three-dimensional periodicity of solids. This chapter describes how this fundamental law has to be revised and generalized in order to include the structures of aperiodic crystals. The generalization consists in using for each face a number of integers, with the number corresponding to the rank of the structure, that is, the number of integer indices necessary to characterize each of the diffracted intensities generated by the aperiodic system. A series of examples including incommensurate multiferroics, icosahedral crystals, and decagonal quaiscrystals illustrates this topic. Aperiodicity is also encountered in surfaces where the same generalization can be applied. The chapter discusses aperiodic crystal morphology, including icosahedral quasicrystal morphology, decagonal quasicrystal morphology, and aperiodic crystal surfaces; magnetic quasiperiodic systems; aperiodic photonic crystals; mesoscopic quasicrystals, and the mineral calaverite.


2005 ◽  
Vol 13 (7) ◽  
pp. 2370 ◽  
Author(s):  
Peng Yao ◽  
Garrett J. Schneider ◽  
Dennis W. Prather ◽  
Eric D. Wetzel ◽  
Daniel J. O'Brien

2020 ◽  
Vol 117 (26) ◽  
pp. 14987-14995 ◽  
Author(s):  
Ratan Othayoth ◽  
George Thoms ◽  
Chen Li

Effective locomotion in nature happens by transitioning across multiple modes (e.g., walk, run, climb). Despite this, far more mechanistic understanding of terrestrial locomotion has been on how to generate and stabilize around near–steady-state movement in a single mode. We still know little about how locomotor transitions emerge from physical interaction with complex terrain. Consequently, robots largely rely on geometric maps to avoid obstacles, not traverse them. Recent studies revealed that locomotor transitions in complex three-dimensional (3D) terrain occur probabilistically via multiple pathways. Here, we show that an energy landscape approach elucidates the underlying physical principles. We discovered that locomotor transitions of animals and robots self-propelled through complex 3D terrain correspond to barrier-crossing transitions on a potential energy landscape. Locomotor modes are attracted to landscape basins separated by potential energy barriers. Kinetic energy fluctuation from oscillatory self-propulsion helps the system stochastically escape from one basin and reach another to make transitions. Escape is more likely toward lower barrier direction. These principles are surprisingly similar to those of near-equilibrium, microscopic systems. Analogous to free-energy landscapes for multipathway protein folding transitions, our energy landscape approach from first principles is the beginning of a statistical physics theory of multipathway locomotor transitions in complex terrain. This will not only help understand how the organization of animal behavior emerges from multiscale interactions between their neural and mechanical systems and the physical environment, but also guide robot design, control, and planning over the large, intractable locomotor-terrain parameter space to generate robust locomotor transitions through the real world.


Sign in / Sign up

Export Citation Format

Share Document