Online Archive of University of Virginia Scholarship
Advancements in Filtering Technology for Large Aperture Cryogenic Detector Arrays8 views
Author
Taffe, Sarah, Physics - Graduate School of Arts and Sciences, University of Virginia0000-0002-1958-4443
Advisors
Neu, Chris, AS-Physics (PHYS), University of Virginia
Johnson, Bradley, AS-Astronomy (ASTR), University of Virginia
Abstract
Next-generation cosmic microwave background (CMB) experiments, such as
the Simons Observatory and the proposed CMB-S4 experiment, require large-format
far-infrared metal mesh filters with aperture diameters of 500–600 mm to manage
the thermal loading on cryogenic detector arrays operating at 0.1 K. The standard
fabrication technique of UV photolithography presents a significant production ob-
struction at these scales, motivating the development of Direct Write Laser Ablation
(DWA) as a mask-free, cost-effective alternative. This thesis investigates the use of
a consumer-grade xTool S1 2W 1064 nm infrared laser to fabricate complementary
inductive (high-pass) and capacitive (low-pass) metal mesh filters on aluminized My-
lar substrates of 0.002 inch (50.8 μm) and 0.005 inch (127 μm) thickness, targeting
a 170–260 GHz band-pass filter for CMB observations. Inductive (high-pass) filters
were successfully fabricated on both substrate thicknesses, while capacitive (low-pass)
grid fabrication was not achieved. Three technical pathways to resolving this problem
were identified as including design pre-processing, relaxed grid geometry, and higher-
resolution laser platforms. These results demonstrate that consumer-grade DWA on
aluminized Mylar is a viable fabrication route for inductive metal mesh filters, with
clear potential for scale-up to the production requirements of large-aperture cryogenic
CMB surveys.
Taffe, Sarah. Advancements in Filtering Technology for Large Aperture Cryogenic Detector Arrays. University of Virginia, Physics - Graduate School of Arts and Sciences, MS (Master of Science), 2026-05-02, https://doi.org/10.18130/amxa-9k84.