Title |
THz filters made by laser ablation of stainless steel and Kapton Film / |
Authors |
Han, Molong ; Smith, Daniel ; Ng, Soon Hock ; Vilagosh, Zoltan ; Anand, Vijayakumar ; Katkus, Tomas ; Reklaitis, Ignas ; Mu, Haoran ; Ryu, Meguya ; Morikawa, Junko ; Vongsvivut, Jitraporn ; Appadoo, Dominique ; Juodkazis, Saulius |
DOI |
10.3390/mi13081170 |
Full Text |
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Is Part of |
Micromachines.. Basel : MDPI. 2022, vol. 13, iss. 8, art. no. 1170, p. [1-15].. eISSN 2072-666X |
Keywords [eng] |
anisotropy ; synchrotron infrared ; THz filters |
Abstract [eng] |
THz band-pass filters were fabricated by femtosecond-laser ablation of 25- (Formula presented.) m-thick micro-foils of stainless steel and Kapton film, which were subsequently metal coated with a ∼70 nm film, closely matching the skin depth at the used THz spectral window. Their spectral performance was tested in transmission and reflection modes at the Australian Synchrotron’s THz beamline. A 25- (Formula presented.) m-thick Kapton film performed as a Fabry–Pérot etalon with a free spectral range ((Formula presented.)) of 119 cm (Formula presented.), high finesse (Formula presented.), and was tuneable over ∼ (Formula presented.) m (at ∼5 THz band) with (Formula presented.) tilt. The structure of the THz beam focal region as extracted by the first mirror (slit) showed a complex dependence of polarisation, wavelength and position across the beam. This is important for polarisation-sensitive measurements (in both transmission and reflection) and requires normalisation at each orientation of linear polarisation. |
Published |
Basel : MDPI |
Type |
Journal article |
Language |
English |
Publication date |
2022 |
CC license |
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