Scholarlink

<p>This study investigates the formation of two types of laser-induced periodic surface structures (LIPSS) on amorphous Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> (GST) using terahertz free-electron laser (THz-FEL) irradiation. The THz pulses used in this study consist of a macro pulse containing 150 micro pulses, each with a duration of 2 ps. The central wavelength λ of the THz radiation is 75 μm. By exposing GST to THz-FEL pulses at fluences up to 35 J/cm<sup>2</sup>, two distinct periodic structures were observed: low spatial frequency LIPSS (LSFL) and high spatial frequency LIPSS (HSFL). The LSFL&#xa0;formed parallel to the laser's polarization direction with a period of&#xa0;approximately λ/4.5. The HSFL, with a period λ/18, formed perpendicular to the polarization near the ablation edges. The periods of the generated HSFL and LSFL are 4 μm and 16 μm, respectively, and can be observed with an optical microscope.&#xa0;The period of the LSFL is generally consistent with λ/<i>n</i> (where <i>n</i> is the material’s refractive index), which is the approximate value expected based on previous reports in the optical region. This work contributes to a deeper understanding of LIPSS formation mechanisms under long-wavelength terahertz irradiation and suggests pathways for fine-tuned surface structuring applications using THz-FEL.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Terahertz pulses generate two types of laser-induced periodic surface structures on phase change material Ge2Sb2Te5

  • 期刊论文

  • 发表日期：

    2025年6月17日

查看全文
  • You Wei Wang,
  • Zihao Yang,
  • Kosaku Kato,
  • Verdad C. Agulto,
  • Thanh Nhat Khoa Phan,
  • Kotaro Makino,
  • Junji Tominaga,
  • Goro Isoyama,
  • Makoto Nakajima

摘要

This study investigates the formation of two types of laser-induced periodic surface structures (LIPSS) on amorphous Ge2Sb2Te5 (GST) using terahertz free-electron laser (THz-FEL) irradiation. The THz pulses used in this study consist of a macro pulse containing 150 micro pulses, each with a duration of 2 ps. The central wavelength λ of the THz radiation is 75 μm. By exposing GST to THz-FEL pulses at fluences up to 35 J/cm2, two distinct periodic structures were observed: low spatial frequency LIPSS (LSFL) and high spatial frequency LIPSS (HSFL). The LSFL formed parallel to the laser's polarization direction with a period of approximately λ/4.5. The HSFL, with a period λ/18, formed perpendicular to the polarization near the ablation edges. The periods of the generated HSFL and LSFL are 4 μm and 16 μm, respectively, and can be observed with an optical microscope. The period of the LSFL is generally consistent with λ/n (where n is the material’s refractive index), which is the approximate value expected based on previous reports in the optical region. This work contributes to a deeper understanding of LIPSS formation mechanisms under long-wavelength terahertz irradiation and suggests pathways for fine-tuned surface structuring applications using THz-FEL.