Oct 23, 2018

Prof. Ted Young on the 'failure of education'

I have moved to King's for a little more than a year now, doing a 'postdoc'. After a long struggle on the choice between 'industry' and 'academia', probably a question every PhD candidate faces, this is the choice I made at the moment.

While research is my main task as a 'research associate', I do respect those who devote to teaching and think about education. what job is more important in the world than to educate and nurture the minds that will shape our society for the next 100, 200 years?
I am reading this speech made by Prof. I. T. Young on the 'failure of education' in the context of Netherlands, but I believe it is quite general to many places.
http://homepage.tudelft.nl/t5g29/manuscripts/Failure%20in%20Education%20-%20IT%20Young.pdf

Feb 20, 2017

Positioning fluorescence microscopy approaching 1nm resolution with the help of optical singularity

I enjoyed quite a lot in reading a nice work from S. Hell's group, namely "Nanometer resolution imaging and tracking of fluorescent molecules with minimal photon fluxes",published recently in Science, but a free version available on arxiv;
The core idea of this paper is to use the absolute zero intensity at the singular point of an ideal donut beam to perform positioning microscopy like PALM/STORM. When fluorescence molecule are exactly at this point, it will emit no photon, the nearer the fluorescent molecule is to the singular point, the emitting photon is less. Finding the minimum of minimum photon emission leads to the determination of the position of the fluorescent molecule. It is really clever idea and a marvelous improvement with much less photon required to achieve 1nm resolution.

Some nice early works applying singular optics to metrology can be found in Joseph Shamir's work "Singular beams in metrology and nanotechnology". And Zheng Xi also proposed to use this singularity to perform position sensing: "Accurate Feeding of Nanoantenna by Singular Optics for Nanoscale Translational and Rotational Displacement Sensing" with a free version on arxiv.

All these demonstrates useful applications of optical singularity, I believe many more nice works will pop out in this field.

Dec 17, 2016

FOM veldhoven

My work is accepted by FOM veldhoven 2017 as an oral presentation and I will talk about our paper on "Excitation of the radiationless anapole mode";

Oct 11, 2016

nice review on the current "meta-lens" researches

"Meta-lens" researches has drawn lots of attentions in recently years. With many contributions from groups with nanotechnology backgrounds, meta-lens are realized by creating a focusing wavefront using structured surfaces like plasmonic structures and high index dielectric structures. However, compared to the overwhelming attentions it got, the drawbacks of such meta-lens from optics perspective are greatly overlooked, similar to the fact that the losses of plasmonic structures are neglected in many publications which produce lots of highly cited papers and create a "closed" subfield of physics but not many real applications comes out.
Finally a nice and critical review is given by diffraction optics experts  P. Lalanne and P. Chavel on the current "Meta-lens" researches.
https://arxiv.org/ftp/arxiv/papers/1610/1610.02507.pdf

Jul 20, 2016

New publication on excitation of the radiationless anapole

My paper on the excitation of the radiationless anapole is just published online in OSA's new open access journal Optica:
Excitation of the radiationless anapole mode
I've made a video recently on this topic for our group website:

May 13, 2016

new publication on stretchable Fresnel zone plate

Xueming's paper on a stretchable Fresnel zone plate composed of CNT grown on PDMS, in which I performed the simulation and optical measurement,  is published on Scientific Reports:
http://www.nature.com/articles/srep25348
Achieving circularly symmetric stretching is rather difficult task, which results in strong astigmatism aberrations after stretching. But it is a very good idea. If we could have found an ideal circular stretching mechanism, it will be much better, #the power of mechanical engineering:).

New publication on focal field shaping of vector vortex beams

Our publication "Shaping the focal field of radially/azimuthally polarized phase vortex with Zernike polynomials" is published recently on Journal of Optics.: 
http://iopscience.iop.org/article/10.1088/2040-8978/18/6/065608