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a public sculpture by Indian-born British artist Anish Kapoor


Beam Reflection THINK BACK TO THE LAST TIME WE SUBMIT TO NATURE PHOTONICS (NPs) . We happily opened a bottle (or few bottles) of wines to celebrate it after we observed the focusing effect. Although it was too early to open the wine for this work, I am grateful that I can work with many people here and never feel lonely during my research life. Unfortunately, the firt attempt to the journal, Nature Photonics, was not successful. A referee from NPs commented: “The authors mentioned that this is a promising result, hinting that spatial dispersion can be reduced to zero or even made negative but this language is weak and vague. The paper feels half-baked. Why didn't they go further?” At least, we are still happy for the editor’s affirmation. Yes, we admit that the chirped mirror can only show “physically” the principle although the focusing effect was not obvious. Afterwards, we improved our work, solved those problems that referees pointed out and try to submit it to NPs again. From our point of views, the story of how a chirped mirror modulate the divergence of beam is really novel and suprising. The chirped

mirror is a well-known devices for a pulse but it unexpectly can be also used for a beam focusing. The strucutre is not fancy enough to attarct much attentions but the simple idea is really beautiful! To be honest, the application is not so appealing due to its limitations, i.e. The focus works only at nonzero angles, only for a beam and only for one direction. The other difficult thing is that the unavoivable fringes effect which results in a narrow angular bandwidth . Therefore, the focusing is too weak to be observed. My final aim is to design a flat focuisng mirror with a revalent focal length which will make the referrees feel well-baked or even over-baked. A famous sculpture in Chicago, a bean reflection, is taken as the highlighting picture here. This giant bean mirror is so eye catching just like how interesting our work is. Surprising, a novel idea is realized with a common device, a chirped mirror. As long as we consider the beam in the angular space which we are not used to, we can see a outstanding view form such magic mirrors.

COAUTHOR LIST: Martynas Peckus

is senior researcher at Vilnius University, Laser Research Center, Lithuania. His major is in spatial light modulation, linear and nonlinear Mini-Resonators, photonic crystals.

Simonas Kicas

is a PhD student at the CPST in the field of thin film coating deposition technologies and dispersive multilayer systems. He is in charge of design and fabrication of flat focusing mirror.

Ramutis Drazdys

is the supervisor of Simonas Kicas at the CPST. He is major in femtolaser, optical thin film and coating technique.


Cojocaru is a associate professor at UPC. Her activity covers, periodic materials, photonic crystals and random nonlinear media and ultrashort pulse, etc. Ramon

Vilaseca is professor at UPC, and coordinator of the research group DONLL. He works in nonlinear optics and dynamics and in photonic crystals.

Profile for Yu-chieh Cheng

Thesis yu chieh cheng 2015  

Thesis yu chieh cheng 2015