Mid-infrared interference coatings with excess optical loss below 10&#x00A0;ppm: erratum

L. W. Perner; L. W. Perner; G. Winkler; G.-W. Truong; G.-W. Truong; G.-W. Truong; G. Zhao; G. Zhao; D. Bachmann; D. Bachmann; A. S. Mayer; J. Fellinger; D. Follman; D. Follman; D. Follman; D. Follman; P. Heu; P. Heu; C. Deutsch; C. Deutsch; D. M. Bailey; H. Peelaers; S. Puchegger; A. J. Fleisher; G. D. Cole; G. D. Cole; G. D. Cole; O. H. Heckl

doi:10.1364/OPTICA.520398

1. LABELING OF CRYSTAL AXES

Fig. 1. Corrected version of Fig. 1 of [1]. See Table 1 for the corrected caption.

In Fig. 1 of our article [1], we report that the $\phi = 0^\circ$ direction—i.e., the direction corresponding to the coating flat—is aligned in parallel to the $[{0} \overline{1}\,\overline{1}]$ crystal axis. This was labeled incorrectly due to a misinterpretation of reference drawings. Instead, the coating flat—corresponding to $\phi = 0^\circ$—is aligned to the $[{01\bar 1}]$ axis. Additionally, $\phi = 270^\circ$ is aligned to the $[{011}]$ crystal axis. This is consistent with a $({\bar 100})$-oriented sample during optical testing.

Table 1. Listing of Necessary Corrections to the Original Manuscript

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This mislabeling is equivalent to a 90° rotation about the $[{100}]$ axis combined with a 180° rotation about the $[{01\bar 1}]$ axis with respect to the original labels. While the structure was indeed grown on a (100)-oriented seed wafer, the top half of the epitaxial structure was flipped during bonding in order to realize the stacked optical coating. This means that the effective crystallographic orientation of the optically probed sample is $({\bar 100})$, consistent with above axis labels.

Fig. 2. Corrected version of Fig. 8 of [1]. See Table 1 for the corrected caption.

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Fig. 3. Corrected version of Fig. 9 of [1]. See Table 1 for the corrected caption.

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The mislabeled axes were also used as a basis for the simulations presented in Section 3.D of the original manuscript. Therefore, we ran the simulations again, now using the correct orientation. The new simulations yield results confirming an identical behavior as originally reported but now consistent with the corrected axis labels.

During experimental work, all measurement orientations were recorded as an angle $\phi$ with respect to the coating flat of the final mirror, corresponding to $\phi$ axis labels in the top middle panel of Fig. 1 and Fig. 8 of our original article, both of which remain unchanged.

Since Fig. 1 was used as a reference for aligning angular measurements with nominal crystal axes throughout the article, several corrections are necessary. These corrections are summarized in Table 1.

Except for the orientation corresponding to minimal excess loss, all findings and conclusions of the original publication remain unchanged by this mislabeling.

2. CORRECT REFERENCE

Furthermore, we correct a reference in the supplement of our published article. The only citation in the published supplement points to Ref. [49] of the main manuscript. However, we intended to cite [2]. This is a typographical oversight and has no influence on the presented results.

REFERENCES

1. G. Winkler, L. W. Perner, G.-W. Truong, et al., “Mid-infrared interference coatings with excess optical loss below 10 ppm,” Optica 8, 686–696 (2021). [CrossRef]

2. J. Courtois and J. T. Hodges, “Coupled-cavity ring-down spectroscopy technique,” Opt. Lett. 37, 3354–3356 (2012). [CrossRef]

Position in Text	Original	Correction
Fig. 1, Caption	The flat is aligned with the $[0 - \bar{1} - \bar{1} -]$ crystal axis.	The flat is aligned with the $[01 \bar{1}]$ crystal axis.
Fig. 1, Figure	Wrong labels in top middle figure, as stated above.	See Fig. 1 below.
Fig. 6, Caption	All measurements were performed for incident linear polarization angle $ϕ = 90^{\circ}$ relative to the $[0 - \bar{1} - \bar{1} -]$ crystal axis.	All measurements were performed for incident linear polarization angle $ϕ = 90^{\circ}$ relative to the $[01 \bar{1}]$ crystal axis.
Fig. 8, Caption	Change in optical losses plotted versus linear polarization angle $ϕ$ relative to the $[0 - \bar{1} - \bar{1} -]$ crystallographic $- p - l - a - n - e -$ .	Change in optical losses plotted versus linear polarization angle $ϕ$ relative to the $[01 \bar{1}]$ crystallographic axis.
Fig. 8, Figure	The labels of the axis labeled “polarization axis” (bottom x-axis) are offset by 90°. The label of the axis labeled “relative polarization angle $ϕ$ (°)” are correct with respect to the coating flat, defined as $ϕ = 0^{\circ}$ in Fig. 1.	See Fig. 2 below.
Fig. 9, Caption	Results are given for a photon energy of 1.2 eV and in-plane compressive strain of 1% along the $[0 - \bar{1} - 1 -]$ direction.	Results are given for a photon energy of 1.2 eV and in-plane compressive strain of 1% along the $[0 \bar{1} \bar{1}]$ direction.
Fig. 9, Figure	The x-axis labels are shifted by a 90° rotation.	See Fig. 3 below.
Main text, Sec. 3.B	As shown in Fig. 8, absorption reaches a minimum for linear pump polarization oriented at a relative angle of $ϕ = 90^{\circ}$ with respect to the $[0 - \bar{1} - \bar{1} -]$ crystal axis (represented by the coating flat) and a maximum for $ϕ = 0$ .	As shown in Fig. 8, absorption reaches a minimum for linear pump polarization oriented at a relative angle of $ϕ = 90^{\circ}$ with respect to the $[01 \bar{1}]$ crystal axis (represented by the coating flat) and a maximum for $ϕ = 0$ .
Main text, Sec. 3.D	However, owing to the cubic nature of the zincblende unit cell, an in-plane biaxial strain for $(- 1 - 0 - 0 -)$ -oriented GaAs, as implemented here, will lower the symmetry from cubic to tetragonal.	However, owing to the cubic nature of the zincblende unit cell, an in-plane biaxial strain for $(\bar{1} 00)$ -oriented GaAs, as implemented here, will lower the symmetry from cubic to tetragonal.
Main text, Sec. 3.D	To test this hypothesis, we simulated the free-carrier absorption caused by an additional 1% strain along the $[0 - \bar{1} - 1 -]$ direction.	To test this hypothesis, we simulated the free-carrier absorption caused by an additional 1% strain along the $[0 \bar{1} \bar{1}]$ direction.

Mid-infrared interference coatings with excess optical loss below 10 ppm: erratum

Abstract

1. LABELING OF CRYSTAL AXES

2. CORRECT REFERENCE

REFERENCES

Cited By

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Tables (1)

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