Hook-method

The second example is the one in fig. 4.3 (see also fig. 8.22), which shows a perturbed series, within which the / values actually fall to zero as a result of an interference effect due to a perturbation. This reduction in oscillator strength put severe demands on experimental technique, despite which measurements were extended up to n = 45, whereas the highest which had previously been achieved [165] by interferometry (the Hook method) was n 15, precluding any quantitative observation of the minimum. 

Fig. 4.33. Combination of Mach-Zehnder interferometer and spectrograph used for the hook method...

W.A. van Wijngaarden, K.D. Bonin, W. Happen Inverse hook method for measuring oscillator strengths for transitions between excited atomic states. Hyperf. Interact. 38, 471 (1987)... 

The Hook Method. The hook method is based on the Kramer-Kroaig dispersion relation, which relates the refractive index of a gas to transition probabilities [9.151, 9.152]. At the same time as atoms in a vapour absorb at... 

The Hook method yields very accurate, rehable relative transition probabilities. A laser-based related technique, the inverse Hook method , has also been introduced [9.153]. 

Laurent explored this hypothesis in the pages of his hook Methode de chimie, published posthumously in 1854. He wrote. 

Fig.2.23. Experimental arrangement for the measurement of dispersion in atomic vapors (hook method)...

Sion close to the absorption lines causes interference patterns behind the Mach-Zehnder interferometer, which can be displayed behind a spectrograph as a function of the wavelength X. This dispersed pattern has the form of hooks (see Fig.2.24, also Fig.4.33), which gave the method its name. With simultaneous detection of absorption and dispersion the density N. of absorbing molecules can be determined. This allows the oscillator strength to be derived from one experiment without additional information [2.17]. Such combined techniques have considerably increased the accuracy and relevance of the hook method. 

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