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large scale meta lenses

Imaging the Cosmos with All-Glass 100mm Metalens

January 18, 2024

Metalenses, or flat lenses, are collections of tiny nanostructures arranged on a flat surface that focus incident light in a similar manner to conventional curved refractive lenses. Although metalenses for visible light can be extremely light and thin compared to their refractive counterparts, a big challenge is that their nanostructures have to be smaller than the wavelength of the light they are manipulating. For visible light, these nanostructures have to be 200 times smaller than a strand of hair. Their tiny geometries also mean that a large diameter lens at the scale of those used...

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Daniel and Joon-Suh with their committees

Dr. Soon Wei Daniel Lim and Dr. Joon-Suh Park successfully defend theses!

December 6, 2023

This fall, Dr. Soon Wei Daniel Lim and Dr. Joon-Suh Park have successfully defended their theses. In their time in the Capasso group, Daniel has been working on singularity engineering with metasurfaces and Joon-Suh has been working on the development of metasurface fabrication protocols for both prototyping and mass production. Additionally, they have made both made invaluable contributions to the work of the entire group group in taking on responsibilities for group servers, this website and fabrication. We are all grateful, and wish both all the best in their future...

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Time-domain optimized 3D resonator

Novel approach for gradient computation in photonic inverse design

November 15, 2023

In the recently published ACS Photonics paper titled "Time Reversal Differentiation of FDTD for Photonic Inverse Design", co-first authors Jerry Tang Rui Jie and Soon Wei Daniel Lim present a novel approach for computing gradients in finite difference time domain (FDTD) simulations for photonic inverse design. Their technique surmounts the memory constraints inherent in automatic differentiation (AD) and preserves the computational efficiency of the state-of-the-art adjoint method. The method calculates gradients by replaying time-dependent fields at lossy boundaries, which significantly...

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Ahmed in the lab

Ahmed Dorrah wins the 2023 Optica Foundation Challenge

October 11, 2023

Dr. Dorrah has received a $100,000 grant from the Optica Foundation for his proposed work entitled: “Structured light generation and sensing with metasurfaces for THz communications”. Ahmed is one of 10 recipients of the award, which provides seed money to early-career professionals to investigate impactful ideas in environment, health, and information. The award money will help build a compact wavefront sensor which can construct 2D maps of the incident THz radiation (including its...

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Polarization gradient trapping

A new principle of optical trapping leveraging the polarization gradient

October 6, 2023

We present new principles underlying optical trapping and manipulation techniques by introducing an additional degree of freedom: the polarization gradient found in evanescent fields. These evanescent fields are common at the micro and nano-scales. When generated by guided modes in integrated waveguides, these evanescent fields exhibit transverse spin and Belinfante momentum. Both of these properties can be harnessed for optical trapping and micromanipulation. Our technique can be integrated with photonic integrated circuits to leverage their rapid construction and widespread deployment...

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4D metasurface under microscope

Two aspects of dark points in light

June 27, 2023

If you shine a laser pointer on a rough surface, you will notice that the reflected light creates a constellation of bright spots. However, less visible among these bright spots are threads of darkness known as optical singularites. Historically, these have been challenging to engineer. This month, the Capasso group has published two papers demonstrating powerful new tools to shape these dark regions using metasurfaces.

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Aun, Federico and Dima after both have successfully defended their theses.

Dr. Aun Zaidi and Dr. Dmitry Kazakov successfully defend theses!

June 9, 2023
We congratulate Dr. Dmitry Kasakov and Dr. Aun Zaidi on successfully defending their PhD theses and graduating this spring! In their time in the Capasso group, Dmitry has been working on active nonlinear mid-infrared photonics and Aun has been working on structuring and imaging polarization transformation using metasurfaces. We wish both all the best in their future scientific endeavors!
Jinsheng PRL

Using resonances as synthetic helicity for optical manipulation

May 1, 2023

Research on spin-orbit interactions in evanescent fields is crucial as it could revolutionize particle manipulation using light. This research, led by Dr Jinsheng Lu and published in Physical Review Letters, has uncovered a new kind of optical force that relies on the polarization of the incoming light or the particle being manipulated. We examined these phenomena in a microfiber-microcavity system with whispering gallery mode resonances, allowing for a clearer understanding and unification of polarization-dependent forces. Our findings challenge previous studies and suggest a...

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