Design of double-reflector objective for corneal sensing in the 220-330 GHz band
A4 Artikkeli konferenssijulkaisussa
2022 16th European Conference on Antennas and Propagation, EuCAP 2022, Proceedings of the European Conference on Antennas and Propagation
AbstractAn all reflective, Schwarzschild objective design for corneal reflectometry is evaluated in the WR3.4 (220-330 GHz) frequency band. The shadow created by the 60-mm diameter secondary mirror is sufficiently large to mount a standard, OCT system to enable concomitant data acquisition with both modalities while avoiding beam obscuration. The system was fed with a bottle beam comprised of a p= 0, ell = 4 Laguerre-Gaussian mode with a 12.5-mm beam waist radius for increased throughput. The 50-mm focal length system was determined with ray tracing and simulated with an in-house physical optics code using a PEC sphere as a test target. The power coupling coefficient between the feed beam and scattered beam varied from 0.35 at 220 GHz to 0.48 at 330 GHz. While the system demonstrated a clear phase center at less than 1 λ from the geometric focal point, significant edge diffraction prevents the formation of a spherical phasefront, which is needed to achieve phase front matching.
Funding Information: The calculations presented above were performed using computer resources within the Aalto University School of Science “Science-IT”. This work is funded by Academy of Finland RADDESS programme (project AGRUM, decision number 327640). Publisher Copyright: © 2022 European Association for Antennas and Propagation.
cornea sensing, Schwarzschild objective, submillimeter waves
Baggio , M , Tamminen , A , Ala-Laurinaho , J & Taylor , Z 2022 , Design of double-reflector objective for corneal sensing in the 220-330 GHz band . in 2022 16th European Conference on Antennas and Propagation, EuCAP 2022 . Proceedings of the European Conference on Antennas and Propagation , IEEE , European Conference on Antennas and Propagation , Madrid , Spain , 27/03/2022 . https://doi.org/10.23919/EuCAP53622.2022.9769685