In principle, the real n and imaginary k parts of the complex refractive index of a crystal can be determined by measuring, when possible, its transmission and reflection spectra. We show that it is possible to derive the frequency dependence of n and k in a simple way by using exact expressions for the interference-free transmittance and reflectance to describe low-resolution data. We also derive n and k data starting from one high-resolution spectrum. As an example, we have measured the room-temperature transmittance and reflectance of MgO in the far-infrared region. Reliable n and k data are then obtained in the frequency region 50-250 cm-1.
REFRACTIVE-INDEX OF CRYSTALS FROM TRANSMISSION AND REFLECTION MEASUREMENTS - MGO IN THE FAR-INFRARED REGION / Cunsolo, S; Dore, Paolo; Varsamis, Cp. - In: APPLIED OPTICS. - ISSN 0003-6935. - STAMPA. - 31:(1992), pp. 4554-4558. [10.1364/AO.31.004554]
REFRACTIVE-INDEX OF CRYSTALS FROM TRANSMISSION AND REFLECTION MEASUREMENTS - MGO IN THE FAR-INFRARED REGION
DORE, Paolo;
1992
Abstract
In principle, the real n and imaginary k parts of the complex refractive index of a crystal can be determined by measuring, when possible, its transmission and reflection spectra. We show that it is possible to derive the frequency dependence of n and k in a simple way by using exact expressions for the interference-free transmittance and reflectance to describe low-resolution data. We also derive n and k data starting from one high-resolution spectrum. As an example, we have measured the room-temperature transmittance and reflectance of MgO in the far-infrared region. Reliable n and k data are then obtained in the frequency region 50-250 cm-1.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
