Dispersion of piezo-optic constants of some alkali halides in the ultraviolet region. I. Determination of absolute values

Abstract

Static and ultrasonic methods are described for the determination of the piezo-optic coefficients, q11-qlz and q44, and the strain-optic ratios, plz/p11 and @11 +p12-2p44)/@11 "~"P12-[-2p44), for NaC1, KC1, KBr and KI. Dispersion of the absolute elasto-optical constants, p11, p12 and p44 is evaluated. Comparison is made with predictions of Bansigir & Iyengar's theory of the piezo-optic effect in cubic crystals. The occurrence of isotropy of birefrigence for uniaxial stress and uniaxial strain at different wavelengths of light is explained.

Dispersion in the Linear and Second‐Order Bond Polarizabilities of Alkali Halides

“…Therefore, to obtain the components bL, pT, f L , and fTas a function of the wavelength it is desirable to employ the values of all three elasto-optic coefficients pll, plz, and p44 from the same work. Such data are available for NaC1, KC1, KBr, and KI [32], unfortunately without any indication of experimental errors. Other experimental works focus attention mainly on the measurements of the dipersion in the relative coefficient p l l -p12 (see, e.g.…”

“…Although the anisotropy changes with wavelength one can note that for the same cation it decreases with the bond length. The dispersion in the components f " and f' obtained employing the elasto-optic coeficients pI1 and p12 from [32] and (l), (2), and (4) to (6) is presented in Fig. 3.…”

“…The wavelength dependence of the components p" and p' evaluated using the elasto-optic data from [32] is presented in Fig. 1.…”

An empirical model of optical susceptibilities of crystals II. Elasto-optical effect in alkali halides

“…Measurements in the visible region (Bansigir and Iyengar, 1961) indicate that for NaCl, KCl, KBr, and KI, pu and p12 increase with increasing wavelengths. However, the dispersion of the same coefficients in these compounds determined near the ultraviolet spectral region (Rahman and Iyengar, 1970) suggests that all elasto-optic quantities become independent of wavelength in the near infrared region. Similar conclusions are obtained from experiments with rubidium compounds (Rahman, 1981).…”

Piezo-optic birefringence in NaCl structure crystals. III

“…The consequences following from the theory were separately dealt in Part II of the paper (Bansigir & Iyengar, 1961b). During recent years new observations relating to the elasto-optic coefficient P44 and the corresponding piezo-optic coefficient q44 have been reported (Laiho & Korpela, 1968;Rahman & Iyengar, 1970). In this paper the theory has been extended on the lines of Part I (Bansigir & Iyengar, 1961a) to cover the related phenomena.…”