dorr_1990 ========= M\. Dörr, R\. M\. Potvliege and R\. Shakeshaft, "Atomic hydrogen irradiated by a strong laser field\: Sturmian basis calculations of rates for high\-order multiphoton ionization, Raman scattering, and harmonic generation", J\. Opt\. Soc\. Am\. B 7, 433 \(1990\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1364/josab\.7\.000433 `__ **Source kind:** theory **Recorded technique:** Atomic hydrogen 1s in a classical, linearly \(or elliptically\) polarised field, dipole approximation\: lowest\-order perturbation theory by a Coulomb Green's function in a complex Sturmian basis \(Sec\. 2; velocity and length gauges compared\), and nonperturbative Floquet \(Sturmian\-Floquet\) quasi\-energies and ionisation rates \(Sec\. 3\) at 532, 608, 616 and 1064 nm, 1e12\-1e14 W/cm^2, with pulse and focal averaging for photoelectron and ion yields\. **Materials in structured entries:** None recorded. **Dataset quantities:** None recorded. **Contents:** 0 datasets; 0 formulas. Curation notes -------------- Pages\: PDF page n is journal page 432 \+ n \(pp\. 433\-448\)\. Identity checked against the first page \(J\. Opt\. Soc\. Am\. B 7, No\. 4, April 1990\)\. NOTHING TAKEN \(methods only, for optmat's purposes\)\. The paper prints no two\-photon quantity\: at its shortest wavelength, 265 nm, ionisation of H\(1s\) needs three photons \(N\_0 = 3; 4, 6 and 12 at 355, 532 and 1064 nm; Table 3\)\. Tables 1\-3 \(p\. 436; tbl\_d4b281340af5, tbl\_6cddcfee798a, tbl\_a857f400c7de\)\: lowest\-order perturbative integrated rates \(s^\-1\) at 1e13 W/cm^2 and 265, 355, 532 and 1064 nm for N\-th order harmonic generation \(N = 3\-33\), N\-th order 1s \-\> 2s Raman scattering and N\-photon ionisation \(N = N\_0 \+ S, S = 0\-8, above\-threshold orders included\)\. 'Perturbation theory is not valid at long wavelengths at the specified intensity, but rates at lower intensities can be easily deduced by using the power law' \(p\. 436\)\. Not taken\: a rate at one nominal intensity in lowest\-order perturbation theory is a generalised cross section times Phi^N, and a cross section would be a conversion, not the printed value; hydrogen's multiphoton rates are not used by optmat's models\. Table 4 \(p\. 437\)\: relative errors of the 16\-photon rate at 1064 nm against basis size \(60, 90, 120 functions; velocity 5\.6e\-4 to 1\.2e\-8, length \-7\.9e\-2 to 4\.3e\-5\)\: the method's convergence, favouring the velocity gauge\. The nonperturbative results \(Figs\. 3\-12\: partial and total rates against intensity, quasi\-energies, photoelectron yields, harmonic rates and the ratio of nonperturbative to perturbative harmonic rates\) are figures only\. 'At long wavelengths and moderate intensities, perturbation theory grossly overestimates the ionization rates' \(abstract\)\. FURTHER TWO\-PHOTON DATA CITED\: none with values\. Above\-threshold perturbative sums follow E\. Karule, J\. Phys\. B 4, L67 \(1971\) and 21, 1997 \(1987\) \(Ref\. 8\); S\. Klarsfeld and A\. Maquet, Phys\. Lett\. 73A, 100 \(1979\) and 78A, 40 \(1980\) \(Refs\. 9, 10\); none in the library\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- No datasets are recorded. 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.