May, 2025, Published in Science
In the CREMA collaboration team, we reported high-precision spectroscopy of muonic helium ions in Science. By replacing the electron with a 200-times-heavier muon in μ³He⁺, we shrank the orbit toward the nucleus and amplified tiny energy shifts, determining the ³He nuclear charge radius to 1.97007 fm—15 times more precise than previous electron-scattering values. This benchmark test of QED and few-body nuclear theory paves the way for even more stringent searches for physics beyond the Standard Model.
我們參與瑞士 CREMA 國際合作,在 《Science》發表渺子氦離子精密光譜成果,首度以渺子 μ³He⁺ 將氦-3 核電荷半徑的測量精度提升 15 倍(1.97007 fm)。渺子質量為電子約 200 倍,使其軌道更貼近原子核,放大能階微擾,為量子電動力學與核力理論提供關鍵驗證,並開闢探索新物理的途徑。
相關科普文章:當渺子取代電子:在原子核系統中的量子縮放帶來的新視野
CREMA Collaboration
March, 2025, Published in ACS Photonics
Overcoming the challenge of generating circularly polarized (CP) light in organic chiral lasers, our recent work introduces a groundbreaking approach by integrating an apparent circular dichroism (ACD)-based thin film into a free-space dye laser cavity. This novel integration achieves direct CP laser emission with a dissymmetry factor (glum) of 1.2—setting a new record for organic chiral lasers. With a high degree of polarization and asymmetric cavity losses driven by the ACD effect, our findings unlock new possibilities for chiral photonic devices, offering a path forward in advancing next-generation laser systems. This breakthrough highlights the potential of ACD-based materials to overcome traditional limitations in chiral lasers.
旋性分子組成的材料一直以來具備產生旋性光的可能,然而其reciprocal本質及鏡面反射物理定律的守恆另其旋性始終無法在光腔中得到放大。我們的最新研究利用新發展的ACD有機薄膜(具non-reciprocal特性),成功突破了傳統有機旋性雷射中生成高純度圓偏振光的困難,得到了1.2的左右圓不對稱因子(glum),創下了有機旋性雷射光的新紀錄。此雷射所產生的偏振度高,且由ACD效應引起的光腔體内右旋和左旋圓偏振光的不對稱損耗進一步增强了雷射光的橢圓度。這一突破為旋性光子元件開啟了新的可能性,並為未來有機雷射系统的發展作為敲門磚,有望用於量子控制及資訊等應用。
我們的研究突顯了基於ACD材料的巨大潛力,及其能夠克服傳統旋性雷射系统的局限性。
Li-Zhi Lin, Ling-Qi Huang, Shi-Wei You, Yi-Jan Huang, Francesco Zinna, Andrew Salij, Lorenzo Di Bari, Randall H Goldsmith, Roel Tempelaar, Chia-Yen Huang, Tzu-Ling Chen*
April, 2024, Published in Nature Communications
We propose a novel approach to engineer asymmetric transmission between left-handed and right-handed circularly polarized light in planar Fabry–Pérot microcavities without requiring nanofabrication. By embedding organic thin films exhibiting apparent circular dichroism (ACD), based on 2D chirality, we achieve significant asymmetry in cavity mode transmission. Our method preserves low mode volumes and enables a range of chiral light-matter phenomena, with potential applications in spintronics, polaritonics, and chiral lasing.
Chen, TL., Salij, A., Parrish, K.A. et al. A 2D chiral microcavity based on apparent circular dichroism. Nat Commun 15, 3072 (2024).
(2022) Published on ACS Photonics (Journal cover)
Chip-scale optical frequency combs can provide broadband spectroscopy for diagnosing complex organic molecules. Here, we apply the Vernier technique to free-running operation of an interband cascade laser frequency comb in a simple linear geometry that performs cavity-enhanced chemical sensing.
(2021) Analytical Chemistry 93(16) 6375-6384
We report a spectrometer employing optically switched dual-wavelength cavity ring-down spectroscopy (OSDW-CRDS) for high-precision measurements of methane isotope ratios. A waveguide optical switch rapidly alternated between two wavelengths to detect absorption by two isotopologues using near-infrared CRDS.
(2021) Nature 93(16) 6375-6384
The size of the helium nucleus has been determined using exotic helium atoms in which one electron has been replaced with its heavier cousin, a muon. The result sheds light on a decade-old puzzle regarding the proton radius.
Find News in https://www.nature.com/articles/d41586-021-00120-0
Tzu-Ling Chen , Andrew Salij , Ms Katherine Parrish , Julia Rasch , Paige Brown , Abitha Dhavamani , Francesco Urraci , Professor Gennaro Pescitelli , Laura Antonella Aronica , Francesco Zinna , Professor Michael Arnold , Michael Wasielewski , Lorenzo Di Bari , Roel Tempelaar, Randall Goldsmith (2024), "A 2D Chiral Microcavity based on Apparent Circular Dichroism." Nature Communications 15 (1), 3072
L. A. Sterczewski*, T.-L. Chen*, D. C. Ober, C. R. Markus, C. L. Canedy, I. Vurgaftman, C. Frez, J. R. Meyer, M. Okumura, and M. Bagheri (2022), "Cavity-enhanced Vernier spectroscopy with a chip-scale mid-infrared frequency comb," ACS Photonics (✿ Journal cover).
Tzu-Ling Chen, Douglas C. Ober, Robin Miri, Thinh Q. Bui, Linhan Shen, Mitchio Okumura (2021) , "Optically switched dual-wavelength cavity ring-down spectrometer for high-precision isotope ratio measurements of methane δd in the near infrared," Analytical Chemistry 93 (16), 6375-6384. (link)
CREMA (Charge Radius Experiment with Muonic Atoms) collaboration (2021), "Measuring the α-particle charge radius with muonic helium-4 ions," Nature, 589, 527–531
Tzu-Ling Chen, Shao-Yu Chang, Yi-Jan Huang, Khemendra Shukla, Yao-Chin Huang, Te-Hwei Suen, Tzu-Yung Kuan, Jow-Tsong Shy, Yi-Wei Liu (2020). “Inverted-ladder-type optical excitation of potassium Rydberg states with hot and cold ensembles,” PHYSICAL REVIEW A, 101, 052507.
Wei-Ling Chen, Tzu-Ling Chen, Yi-Wei Liu (2019). “Sideband amplitude modulation absorption spectroscopy of CH4 at 1170 nm,” Optics Express, 27(15),21264.
CREMA collaboration (2018). “The next generation of laser spectroscopy experiments using light muonic atoms,” Journal of Physics: Conference Series, 1138, 012010
Yi-Jan Huang, D.N. Patel, Tzu-Ling Chen, Yao-Chin Huang, Yung-Chun Chan, Celine Nauer,b, Yi-Wei Liu, Li-Bang Wangb, Jow-Tsong Shy (2018). “Watt level single frequency tapered amplifier laser using narrow band interference filter,” Applied Optics, 57 (24), 7038-7044
CREMA collaboration (2018). “On the double peak structure of avalanche photodiode response to monoenergetic x-rays at various temperatures and bias voltages,” Journal of Instrumentation, 13(01), C01033
Tzu-Ling Chen and Yi-Wei Liu (2017). “Sub-Doppler resolution near-infrared spectroscopy at 1.28 μm with the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy method,” Optics Letter, 42(13), 2447-2450
Tzu-Ling Chen and Yi-Wei Liu (2015). “Noise-immune cavity-enhanced optical heterodyne molecular spectrometry on N2O 1.283 μm transition based on a quantum-dot external-cavity diode laser,” Optics Letter, 40(18),4352-4355
Tzu-Ling Chen, Chang-Yi Lin, Jow-Tsong Shy, and Yi-Wei Liu (2013). “Tunable frequency-stabilization of an ultraviolet laser using a hollow-cathode lamp of atomic thallium,” JOSA B, 30(11), 2966-2969
Tzu-Ling Chen, Isaac Fan, Hsuan-Chen Chen, Chang-Yi Lin, Shih-En Chen, Jow-Tsong Shy, and Yi-Wei Liu (2012). “Absolute frequency measurement of the 6P1/2 → 7S1/2 transition in thallium,” PHYSICAL REVIEW A, 86(5), 052524(7)
Isaac Fan, Tzu-Ling Chen, Yu-Sheng Liu, Yu-Hung Lien, Jow-Tsong Shy, and Yi-Wei Liu (2011). “Prospects of laser cooling in atomic thallium,” PHYSICAL REVIEW A, 84(4), 042504(6)