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Title: HfO 2 -based platform for high-index-contrast visible and UV integrated photonics
Ultraviolet and visible integrated photonics enable applications in quantum information, sensing, and spectroscopy, among others. Few materials support low-loss photonics into the UV, and the relatively low refractive index of known depositable materials limits the achievable functionality. Here, we present a high-index integrated photonics platform based on HfO2and Al2O3composites deposited via atomic layer deposition (ALD) with low loss in the visible and near UV. We show that Al2O3incorporation dramatically decreases bulk loss compared to pure HfO2, consistent with inhibited crystallization due to the admixture of Al2O3. Composites exhibit refractive indexnfollowing the average of that of HfO2and Al2O3, weighted by the HfO2fractional compositionx. Atλ = 375 nm, composites withx = 0.67 exhibitn = 2.01, preserving most of HfO2’s significantly higher index, and 3.8(7) dB/cm material loss. We further present fully etched and cladded waveguides, grating couplers, and ring resonators, realizing a single-mode waveguide loss of 0.25(2) dB/cm inferred from resonators of 2.6 million intrinsic quality factor atλ = 729 nm, 2.6(2) dB/cm atλ = 405 nm, and 7.7(6) dB/cm atλ = 375 nm. We measure the composite’s thermo-optic coefficient (TOC) to be 2.44(3) × 10−5RIU/°C nearλ = 397 nm. This work establishes (HfO2)x(Al2O3)1−xcomposites as a platform amenable to integration for low-loss, high-index photonics spanning the UV to NIR.  more » « less
Award ID(s):
2301389
PAR ID:
10621279
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Optica
Date Published:
Journal Name:
Optics Letters
Volume:
50
Issue:
10
ISSN:
0146-9592
Page Range / eLocation ID:
3165
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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