Achromatic Deep Ultraviolet Lens Using Novel Optical Materials. Issue 8 (8th April 2020)

• Record Type: Journal Article
• Authors: Minami, Yuki; Cadatal-Raduban, Marilou; Kuroda, Koki; Shinohara, Keito; Lai, Youwei; Yamanoi, Kohei; Sarukura, Nobuhiko; Shimizu, Toshihiko; Ishii, Ryota; Kawakami, Yoichi; Kabasawa, Nobuo; Amano, Takashi; Kiyohara, Kosuke; Kiyohara, Motosuke
• Is Part Of: Physica status solidi. Volume 257:Issue 8(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-08
• Subjects: achromatic lenses -- deep ultraviolet -- fluoride crystals -- objective lenses -- wide bandgap; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201900480
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : The development of an achromatic lens in the deep ultraviolet (DUV) region is reported. The dispersion and Abbe numbers of lithium calcium aluminum fluoride (LiCaAlF6 ), magnesium fluoride (MgF2 ), lithium fluoride (LiF), calcium fluoride (CaF2 ), and fused silica (SiO2 ) are investigated in the wavelength range from 200 to 300 nm to determine appropriate material combinations for minimizing chromatic aberration in a doublet. Based on the results of these investigations, a prototype DUV objective lens is fabricated using a LiCaAlF6 (convex lens)SiO2 (concave lens) doublet. The objective lens has a focal length of 10 mm, working distance of 2 mm, and numerical aperture (NA) of 0.2. The objective lens is evaluated to have a chromatic aberration of about 2.8% and resolution of at least 2 μm. It is also evaluated to have a smaller spherical aberration compared with a reflective objective lens with a similar NA. Abstract : An achromatic lens in the deep ultraviolet region is developed using a LiCaAlF6 (convex)SiO2 (concave) doublet. The objective lens has a focal length of 10 mm, working distance of 2 mm, numerical aperture (NA) of 0.2, chromatic aberration of ≈2.8%, and resolution >2 μm. It has smaller spherical aberration compared with a reflective objective lens of a similar NA.