Abstract
We fabricated a 302 mm diameter low-pass filter made of alumina that has an anti-reflection coating (ARC) made with laser-ablated sub-wavelength structures (SWS). The filter has been integrated into and is operating with the MUSTANG2 instrument, which is coupled to the Green Bank Telescope. The average transmittance of the filter in the MUSTANG2 operating band between 75 and 105 GHz is 98%. Reflective loss due to the ARC is 1%. The difference in transmission between the s- and p-polarization states is less than 1%. To within 1% accuracy we observe no variance in these results when transmission is measured in six independent filter spatial locations. The alumina filter replaced a prior MUSTANG2 Teflon filter. Data taken with the filter heat sunk to its nominal 40 K stage show performance consistent with expectations: a reduction of about 50% in filters-induced optical power load on the 300 mK stage, and in in-band optical loading on the detectors. It has taken less than 4 days to laser-ablate the SWS on both sides of the alumina disk. This is the first report of an alumina filter with SWS ARC deployed with an operating instrument, and the first demonstration of a large area fabrication of SWS with laser ablation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 41745-41765 |
| Number of pages | 21 |
| Journal | Optics Express |
| Volume | 29 |
| Issue number | 25 |
| DOIs | |
| State | Published - Dec 6 2021 |
Bibliographical note
Funding Information:Funding. Japan Science and Technology Agency (JPMJCE1313, JPMXS0118067246); National Science Foundation (ECCS-2025124); Japan Society for the Promotion of Science (18KK0083); Council for Science, Technology and Innovation (P16011).
Funding Information:
We acknowledge the World Premier International Research Center Initiative (WPI), MEXT, Japan, for support through Kavli IPMU. This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) project "Development of advanced laser processing with intelligence based on high brightness and high efficiency laser technologies" (P16011) by the Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), "Photonics and Quantum Technology for Society 5.0", and by the Center of Innovation Program, from Japan Science and Technology Agency, JST (JPMJCE1313). This research was also supported by MEXT Q-LEAP (Grant No. JPMXS0118067246) and JSPS KAKENHI Grant Numbers 18KK0083. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nanotechnology Coordinated Infrastructure (NNCI) under Award Number ECCS-2025124.
Funding Information:
Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nanotechnology Coordinated Infrastructure (NNCI) under Award Number ECCS-2025124.
Funding Information:
This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) project "Development of advanced laser processing with intelligence based on high brightness and high efficiency laser technologies" (P16011) by the Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), "Photonics and Quantum Technology for Society 5.0", and by the Center of Innovation Program, from Japan Science and Technology Agency, JST (JPMJCE1313). This research was also supported by MEXT Q-LEAP (Grant No. JPMXS0118067246) and JSPS KAKENHI Grant Numbers 18KK0083.
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