collaborators

6 papers

physics.optics2026

Material selection for mid-infrared thin-film coatings and windows

Jin-Woo Cho, Tanuj Kumar, Hongyan Mei +1

We summarized the room-temperature optical properties for infrared-transparent materials, defining transparency windows for two different applications: thin-film coatings (absorpti…

physics.optics2026

Silicon-on-sapphire metasurfaces generate arrays of dark and bright traps for neutral atoms

Chengyu Fang, Minjeong Kim, Hongyan Mei +10

We demonstrated crystalline silicon-on-sapphire (c-SOS) metasurfaces that convert a Gaussian beam into arrays of complex optical traps, including arrays of optical bottle beams tha…

physics.optics2026

Anti-reflection coatings for highly anisotropic materials in the mid infrared

Hongyan Mei, Jin-Woo Cho, Jae-Seon Yu +6

We develop and optimize thin anti-reflection coatings (ARCs) for highly anisotropic materials in the mid infrared. Unlike conventional ARCs that assume nearly isotropic refractive…

physics.optics2025

Preventing overfitting in infrared ellipsometry using temperature dependence: fused silica as a case study

Shenwei Yin, Jin-Woo Cho, Demeng Feng +6

Fitting oscillator models to variable-angle spectroscopic ellipsometry (VASE) data can lead to non-unique, unphysical results. We demonstrate using temperature-dependent trends to…

physics.optics2025

Self-referencing photothermal common-path interferometry to measure absorption of Si3N4 membranes for laser-light sails

Tanuj Kumar, Demeng Feng, Shenwei Yin +12

Laser-light sails are a spacecraft concept wherein lightweight "sails" are propelled by high-intensity lasers. We investigated the near-infrared absorption of free-standing membran…

cond-mat.mtrl-sci2025

Tuning the surface energy of fluorinated diamond-like carbon coatings via plasma immersion ion implantation plasma-enhanced chemical vapor deposition with 1,1,1,2-tetrafluoroethane

Yuhan Tong, Maryam Zahedian, Aiping Zeng +6

We demonstrate an environmentally friendly and scalable method to create fluorine-doped diamond-like carbon (F-DLC) coatings using plasma immersion ion implantation plasma-enhanced…