Photonics & Lithography Lab

Advancing the frontiers of Nanostructures, Metasurfaces, and Computational Lithography.

Lab Highlights & News

Optics Express Editor's Pick: High-Contrast EUV Imaging with Topological Quasi Phase-Only Masks
Editor's Pick Aug 2026

Optics Express Editor's Pick: High-Contrast EUV Imaging with Topological Quasi Phase-Only Masks

Our paper "High-contrast EUV imaging enabled by topological quasi phase-only masks" has been selected as an Editor's Pick in Optics Express — congratulations to lead author Po-Hsun Fang and the team at NYCU and at TSMC. EUV lithography keeps running into the same wall: the low-k₁ resolution limit. This work pushes through it from two directions. (1) A new kind of EUV mask: instead of relying on absorption, we use a low-n / low-k, Mo-based quasi phase-only mask that modulates phase to lift image contrast and NILS beyond what conventional absorber masks allow — while staying compatible with existing fab processes. (2) A fast inverse-design (ILT) flow: topological phase-mask patterns are only useful if you can actually synthesize them, so we built an inverse-design pipeline that makes these masks practical to generate, not just to theorize. Grateful to the TSMC EBO department for their collaboration and insight throughout this work.

Congratulations! Hsueh-Li Liu (劉學澧) Passes Ph.D Defense!📷 2
Milestone Apr 21, 2026

Congratulations! Hsueh-Li Liu (劉學澧) Passes Ph.D Defense!

Warmest congratulations to Hsueh-Li Liu (Jack) on successfully passing his Ph.D defense on April 21, 2026! Jack's dedication and outstanding research have been an inspiration to the entire PAL Lab. We are incredibly proud of this achievement and wish him all the best in his future endeavors!

ASML Best Student Paper Award at SPIE Advanced Lithography 2026📷 3
Award Feb 2026

ASML Best Student Paper Award at SPIE Advanced Lithography 2026

Congratulations to Chao-Wei Huang for winning the ASML Best Student Paper Award at 2026 SPIE Advanced Lithography and Patterning Conference! Paper title: "Exploiting phase-shifting low-n, low-k absorbers for dense contact hole patterning in EUV lithography".

2026 PAL Lab Spring Party
Lab News Feb 2026

2026 PAL Lab Spring Party

PAL Lab celebrated the 2026 Spring Party! Lab members gathered together to enjoy great food and fun activities, welcoming the new year with warmth and laughter.

OPC+ Cloud Service Now Available
Platform Launch Jan 2026

OPC+ Cloud Service Now Available

Our team has developed a general-purpose OPC cloud service for freeform mask correction. Easy access, easy use - designed for everyone.

2025 Christmas Gift Exchange📷 6
Lab News Dec 25, 2025

2025 Christmas Gift Exchange

PAL Lab celebrated Christmas 2025 with a fun gift exchange party! Lab members gathered together to share joy and exchange gifts, strengthening our lab family bonds.

ASML Best Student Paper Award at SPIE Advanced Lithography 2025📷 2
Award Feb 2025

ASML Best Student Paper Award at SPIE Advanced Lithography 2025

Congratulations to Po-Hsun Fang for winning the ASML Best Student Paper Award at SPIE Advanced Lithography + Patterning 2025! Research title: "Quasi Phase Only Mask for high contrast EUV imaging".

Student Paper Awards at OPTIC 2025
Award Dec 2025

Student Paper Awards at OPTIC 2025

Congratulation to Shang-Chiang Sung to win the student award in OPTIC 2025! Optical Nano Device and Application. Title: Apodized Metasurface Exit-Pupil Expansion Waveguide for High-Efficiency Augmented Reality Glasses

Student Paper Awards at OPTIC 2025
Award Dec 2025

Student Paper Awards at OPTIC 2025

Congratulation to Ping-Ke Li to win the student award in OPTIC 2025! Optical Nano Device and Application. Title: Polarization-Controlled Meta-Holography via large area Chiral Metasurfaces

New Publication Apr 2025

Breakthrough in AR Waveguides

Published in *Metrology, Inspection, and Process Control*: "Large area metalens and AR waveguides fabricated by DUV KrF lithography".

About Our Lab

Take a glimpse into our research environment, facilities, and the collaborative spirit that drives innovation at PAL Lab.

Welcome to PAL Lab

PAL Lab Group Photo

PAL Lab Team

Led by Prof. Peichen Yu at National Yang Ming Chiao Tung University, our lab specializes in the intersection of photonics and advanced lithography. We combine theoretical design with practical fabrication to create next-generation optical devices, from AR waveguides to quantum solutions.

Latest Highlights

  • Editor's Pick!! "High contrast EUV imaging enabled by topological quasi phase-only masks" selected in Optics Express
  • New Publication in *Optics Express*!! "High contrast EUV imaging enabled by topological quasi phase-only masks"
  • Congratulations! Hsueh-Li Liu (Jack) successfully passes his Ph.D defense on April 21, 2026!
  • Congratulations! Chao-Wei Huang wins ASML Best Student Paper Award at 2026 SPIE Advanced Lithography and Patterning Conference
  • 2026 PAL Lab Spring Party - Celebrating the New Year Together!
  • Launched OPC+ Cloud Service for general-purpose freeform mask correction
  • New Publication Accepted!! *Intelligent Proximity Correction Enabled Large-Area Metasurfaces by KrF Photolithography*
  • Congratulations! Student Paper Awards at OPTIC 2025 - Ping-Ke Li & Shang-Chiang Sung
  • New publication in *Optical and EUV Nanolithography XXXVIII* (2025)
  • Breakthrough in Meta-Optics Element Augmented Reality (AR) Waveguides
  • Congratulations! Po-Hsun Fang wins ASML Best Student Paper Award at SPIE Advanced Lithography 2025
  • Congratulations! Yu-Chia Chang wins 2nd place at 2025 SPIE AR|VR|MR Optical Design Challenge
  • Advanced research in Quantum Annealing for lithography optimization
Meet Our Team
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