No abstract

The resonant secondary radiation spectrum of impurity centres in crystals is studied on the basis of a second-order approximation for the interaction between the electromagnetic field and the material. It is shown that for the case of excitation in the phonon wing of the absorption band, the main part of the secondary radiation represents the ordinary luminescence. The spectrum also contains Rayleigh and Raman scattering which is considerably weaker (by about four orders of magnitude). Formulas are obtained for the intensities of Rayleigh-and Rsman scattering ; particular consideration is made for the case of large Stokes' losses. It is also shown that excitation in the region of the pureelectronic line yields a spectrum consisting of the Rayleigh and the pure-electronic line, and the phonon wing of the luminescence. PaCCMOTpeH CIIeKTp pe30HaHCHOrO BTOPH'IHOrO CBeqeHUR KPUCTanJIOB, IIC-XOAR U 3 (POpMyJIbI BTOpOrO IIOpHnHa IIO B3aUMO~efiCTBUIO 3JIeKTPOMarHIlTHOl'O IIOJIR C BeweCTBOM. nOKa3aH0, 'IT0 B CJIy'Iae B036ymAeHHs B (POHOHHOM KpbIJIe IIOJIOCbI IIOrnOweHPiH OCHOBHOB 'IaCTbIO BTOPUYHOrO CBeqeHUfi RBJIReTCFI JIIOMU-HeCUeHUUII. OAHOBpeMeHHO CIleKTp COAepHCHT Il CyUeCTBeHHO 6onee cna6are RJIH UHTeHCUBHOCTefi PeJIeeBCKOrO II KOM6EIHaUHOHHOrO PaCCeRHElfi. Oco6oe BHUcnysae B036YHCAeHWH B o6nac~1l 'IUCTO-3jIeKTPOHHO~ JIUHUU CIIeKTp COCTOIlT U3 PeJIeeBCKOfi U 9EiCTO-3JIeKTPOHHOfi JIHHIld U (POHOHHOI'O KpbIJIa JIH)MUHeCUeHUUU. (B 2 104 pa3) peneeBcKoe ri KOM6IlHaqHOHHOe paccesaas. rIonyseHM @OPMYJIEJ Mame yneneHo cnysam 60nbm~x CTOKCOB~IX noTepb. r I o~a 3 a~o TaKme, w o B

A new method of considering quadratic vibronic interactions and deviations from the Condon approximation in resonance Raman scattering (RRS) is proposed. The method is used for the generalization of the transform law between absorption and Raman excitation profiles, derived earlier for a basic model. In the case of arbitrary mixing of modes with similar frequencies, a simple generalization of the transform law for first-order RRS is obtained. For an arbitrary change of frequencies without mode mixing the transform law for the nth-order RRS is given. The equations are valid for an arbitrary number of modes and also take temperature effects into account.

No abstract