van_der_linden_2025 =================== R\. van der Linden, N\. Kuzkova and P\. M\. Kraus, "Nonlinear refractive index measurements of solids and the impact of B\-integral on the phase of generated high\-order harmonics", Opt\. Express 33, 53268 \(2025\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1364/oe\.579736 `__ **Source kind:** measurement **Recorded technique:** Birefringent common\-path interferometry \(TWINS\: two pairs of alpha\-BBO wedges\) with a Ti\:sapphire amplifier \(Coherent Astrella\) centred at 804 nm, 1 kHz; the pulse duration before focus measured by SHG FROG as a Gaussian FWHM of 47 \+\- 1 fs \(p\. 53271\)\. Two phase\-locked, spatially separated \(247 um\) pulse copies of adjustable intensity ratio are focused \(f = 50 cm spherical mirror, 1/e^2 areas 6\.45e3 and 6\.73e3 um^2\) into 5\-mm\-thick uncoated Thorlabs windows at the focus; the relative phase of the central interference fringe against the normalized intensity difference Delta I/I0 gives n2 from its slope a, n2 = a lambda / \(2 pi L\) \(Eq\. 3, p\. 53272\)\. Six peak intensities, 24 to 55 GW/cm^2, per sample; a sample\-free background phase is subtracted at each intensity \(p\. 53272\)\. **Materials in structured entries:** BK7, CaF2, KBr, N\-BK7, SiO2 **Dataset quantities:** nonlinear\_index **Contents:** 8 datasets; 0 formulas. Curation notes -------------- Journal pages 53268\-53278 = PDF pages 1\-11\. Identity checked against the first page\. DEFINING RELATION \(p\. 53269\)\: P\(3\) = 3 eps0 sum chi\(3\)\_ijkl\(omega; omega, omega, \-omega\) E\_j E\_k E\_l\*, n~\(r, t\) = n0 \+ n2 I\(r, t\) \(Eq\. 1\) with n2 = 3 chi\(3\) / \(4 n0^2 eps0 c\) for isotropic media and parallel linear polarizations; B = \(2 pi / lambda\) int n2 I\(z\) dz \(Eq\. 2\)\. SI units; the tabulated n2 is in 10^\-16 cm^2/W \(Table 1 header, checked on the image\)\. Each pulse copy acquires its own B\-integral in the sample \(the two foci are 247 um apart\), so n2 is the self coefficient\. Both copies are s\-polarized \(linear\) after the polarizer that makes them interfere \(p\. 53270\)\. CORRECTIONS APPLIED BY THE AUTHORS \(p\. 53273\)\: Fourier\-optics simulations showed that the phase measured at the camera is systematically lower than that applied in focus, n2\_in/n2\_out = 1\.9, and that the camera's time averaging over the Gaussian pulse lowers it further, n2\_out,FT/n2\_out,G = 1\.4; 'Both factors are taken into account for the final n2, as presented in Fig\. 4 and outlined in Table 1\.' The tabulated values are averages over the six intensities, from the central fringe only \(p\. 53272\)\. No trend with intensity \(no self\-focusing\), and constant transmission \(no nonlinear absorption\)\. WAVELENGTH\. The laser is centred at 804 nm \(p\. 53270, abstract\); Table 1 prints 800 nm for this work, recorded as printed \(0\.5 % from 804 nm\)\. PART\. 47 fs pulses; the paper does not discuss the Raman \(nuclear\) response\: part = 'unknown'\. UNCERTAINTY\. 'Uncertainties of the reported values from this work are defined as \+\-2 sigma\. As for the references, no explicit definition was given' \(Table 1 note\)\. From error propagation of every measured parameter, the intensity calibration dominating; 'no correlation between uncertainty in I1 and I2 was assumed, which \.\.\. makes the given uncertainty an upper bound' \(p\. 53273\)\. LITERATURE \(Table 1\)\. Z\-scan values of Ref\. \[27\] \(Ensley & Bambha 2019, ensley\_2019\) for CaF2, SiO2 and NBK\-7 at 800 nm, and of Ref\. \[41\] \(DeSalvo et al\. 1996, desalvo\_1996\) for KBr at 1064 nm\. Ensley's own table \(ensley\_2019\) prints these 800 nm values without an uncertainty; the \+\-15 % here \(1\.8 \+\- 0\.27, 2\.7 \+\- 0\.41, 3\.3 \+\- 0\.50\) is van der Linden's reading\. DeSalvo prints KBr at 1064 nm as \(29 \+\- 6\) x 10^\-14 esu with n0 = 1\.53 \(its Tables I\-II\); 7\.87 \+\- 1\.62 x 10^\-16 cm^2/W is van der Linden's conversion \(40 pi n2\(esu\) / \(c n0\) gives 7\.95 \+\- 1\.64 with n0 = 1\.53; computed here 2026\-09\-26; the paper does not state the n0 it used, 7\.87 corresponds to n0 about 1\.545\)\. SAMPLES \(p\. 53271\)\: 5\-mm\-thick uncoated Thorlabs 'isotropic windows'; grades and glass maker not stated\. 'NBK\-7' is recorded as N\-BK7 \(the lead\- and arsenic\-free BK7\)\. refractiveindex\.info \(VanderLinden n2 pages, checked 2026\-09\-26\)\: BK7 \(from NBK\-7\) 3\.33e\-20, CaF2 1\.47e\-20 and SiO2 2\.54e\-20 m^2/W at 0\.804 um, 47 fs\: the same values; the page uses the 804 nm laser wavelength where the table prints 800 nm, files N\-BK7 under BK7, and has no page for KBr \(8\.98e\-20\)\. Section 3\.2 \(HHG in gas, the B\-integral of the fundamental\) holds no material values\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- van\_der\_linden\_2025/twins\_CaF2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "twins_CaF2", "material": "CaF2", "file": "CaF2/van_der_linden_2025__twins_CaF2.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "primary", "uncertainty": { "column": true, "level": "2 sigma" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "common-path (TWINS) interferometry", "pulse_fs": 47, "polarization": "linear", "form": "bulk" } } Table 1, this work \(TWINS\), average over 24\-55 GW/cm^2; 5 mm Thorlabs window\. Laser centred at 804 nm \(printed 800\)\. van\_der\_linden\_2025/twins\_SiO2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "twins_SiO2", "material": "SiO2", "file": "SiO2/van_der_linden_2025__twins_SiO2.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "primary", "uncertainty": { "column": true, "level": "2 sigma" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "common-path (TWINS) interferometry", "pulse_fs": 47, "polarization": "linear", "form": "bulk" } } Table 1, this work \(TWINS\), average over 24\-55 GW/cm^2; 5 mm Thorlabs window, grade not stated\. Laser centred at 804 nm \(printed 800\)\. van\_der\_linden\_2025/twins\_N\-BK7 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "twins_N-BK7", "material": "N-BK7", "file": "N-BK7/van_der_linden_2025__twins_N-BK7.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "primary", "uncertainty": { "column": true, "level": "2 sigma" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "common-path (TWINS) interferometry", "pulse_fs": 47, "polarization": "linear", "form": "bulk" } } Table 1, this work \(TWINS\), printed 'NBK\-7'; average over 24\-55 GW/cm^2; 5 mm Thorlabs window\. Laser centred at 804 nm \(printed 800\)\. van\_der\_linden\_2025/twins\_KBr ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "twins_KBr", "material": "KBr", "file": "KBr/van_der_linden_2025__twins_KBr.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "primary", "uncertainty": { "column": true, "level": "2 sigma" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "common-path (TWINS) interferometry", "pulse_fs": 47, "polarization": "linear", "form": "bulk" } } Table 1, this work \(TWINS\), average over 24\-55 GW/cm^2; 5 mm Thorlabs window\. Laser centred at 804 nm \(printed 800\)\. van\_der\_linden\_2025/ensley\_2019\_CaF2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ensley_2019_CaF2", "material": "CaF2", "file": "CaF2/van_der_linden_2025__ensley_2019_CaF2.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "reproduced", "reproduced_from": [ "ensley_2019" ], "uncertainty": { "column": true, "level": "not stated" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "z-scan" } } Table 1, Z\-scan value of Ref\. \[27\] \(Ensley & Bambha 2019\) at 800 nm; the \+\- is van der Linden's \(Ensley prints none at 800 nm; source notes\)\. van\_der\_linden\_2025/ensley\_2019\_SiO2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ensley_2019_SiO2", "material": "SiO2", "file": "SiO2/van_der_linden_2025__ensley_2019_SiO2.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "reproduced", "reproduced_from": [ "ensley_2019" ], "uncertainty": { "column": true, "level": "not stated" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "z-scan" } } Table 1, Z\-scan value of Ref\. \[27\] \(Ensley & Bambha 2019\) at 800 nm; the \+\- is van der Linden's \(source notes\)\. van\_der\_linden\_2025/ensley\_2019\_BK7 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "ensley_2019_BK7", "material": "BK7", "file": "BK7/van_der_linden_2025__ensley_2019_BK7.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "reproduced", "reproduced_from": [ "ensley_2019" ], "uncertainty": { "column": true, "level": "not stated" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "z-scan" } } Table 1, Z\-scan value of Ref\. \[27\] \(Ensley & Bambha 2019\) at 800 nm, printed on the NBK\-7 row; recorded under BK7, the material of the original \(Ensley and Bambha print 'BK7', from Thorlabs, and do not say N\-BK7; ensley\_2019\)\. The \+\- is van der Linden's \(source notes\)\. van\_der\_linden\_2025/desalvo\_1996\_KBr ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "desalvo_1996_KBr", "material": "KBr", "file": "KBr/van_der_linden_2025__desalvo_1996_KBr.csv", "table": "tbl_a71e46ef0edc", "quantity": "nonlinear_index", "unit": "cm2/W", "scale": 1e-16, "abscissa_unit": "nm", "use": "reproduced", "reproduced_from": [ "desalvo_1996" ], "uncertainty": { "column": true, "level": "not stated" }, "parameters": { "part": "unknown", "coefficient": "self", "technique": "z-scan", "pulse_fs": 30000 } } Table 1, Z\-scan value of Ref\. \[41\] \(DeSalvo et al\. 1996\) at 1064 nm\: van der Linden's conversion of DeSalvo's \(29 \+\- 6\) x 10^\-14 esu \(source notes\)\. DeSalvo's pulses\: 30 ps at 1064 nm\. Formulas -------- No formulas are recorded. Corrections ----------- No dataset errata are recorded in this source record. Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register ` for the checks and decisions.