Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore
doi:10.3850/978-981-18-6021-8_OR-15-0119
Ultraviolet Harmonic Beam Control via Spatial Phase Modulation of Driving Wavelength
1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon, Republic of Korea
ABSTRACT
Beam manipulation of short wavelength light sources, e.g., ultraviolet (UV) to extreme ultra-violet (EUV), is important in various industrial and research applications such as lithography, defect inspection, optical data storage, or encryption. However, beam control of those wavelength regimes is a challenging task due to the strong absorption characteristics of sub-UVs and lack of refractive-based optics. In this paper, we propose novel beam control method from UV to DUV wavelength based on nonlinear harmonic generation, which can emit a shorter wavelength than that of a driving beam. By controlling the spatial phase of the two driving beams using a spatial light modulator (SLM) and irradiating them non-collinearly to the nonlinear medium, we controlled UV second harmonics in real-time, while separating them from the driving beam. Based on the polarization-dependent phase controllability of SLM, harmonic waves can be switched to two different shapes by changing the polarization state of the driving beams. We also present the beam control of the third harmonics (deep-UV, 266 nm) using the MgO medium. This study presents a reliable platform for active spatial control of UV and DUV harmonics without special optical components for those wavelengths.
Keywords: Ultraviolet, beam control, Spatial light modulator
1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon, Republic of Korea
ABSTRACT
Beam manipulation of short wavelength light sources, e.g., ultraviolet (UV) to extreme ultra-violet (EUV), is important in various industrial and research applications such as lithography, defect inspection, optical data storage, or encryption. However, beam control of those wavelength regimes is a challenging task due to the strong absorption characteristics of sub-UVs and lack of refractive-based optics. In this paper, we propose novel beam control method from UV to DUV wavelength based on nonlinear harmonic generation, which can emit a shorter wavelength than that of a driving beam. By controlling the spatial phase of the two driving beams using a spatial light modulator (SLM) and irradiating them non-collinearly to the nonlinear medium, we controlled UV second harmonics in real-time, while separating them from the driving beam. Based on the polarization-dependent phase controllability of SLM, harmonic waves can be switched to two different shapes by changing the polarization state of the driving beams. We also present the beam control of the third harmonics (deep-UV, 266 nm) using the MgO medium. This study presents a reliable platform for active spatial control of UV and DUV harmonics without special optical components for those wavelengths.
Keywords: Ultraviolet, beam control, Spatial light modulator
