Harmonics and subharmonics of a grating inBi₁₂SiO₂₀

摘要

The formation of gratings in photorefractive materials has beenwidely investigated over two decades for applications in non-linearoptics, optical signal processing, optical storage and dynamicholography. Bismuth silicon oxide, Bi₁₂SiO₂₀, withits high sensitivity and fast response, has emerged as a very promisingmaterial for real-time applications. It is shown that when twofrequently detuned pump beams of equal intensity are incident on a BSOcrystal, output beams corresponding to higher harmonics and subharmonicsof the fundamental grating are produced. It is suggested that in orderto explain theoretically all of the observed effects, the higher Fourierterms in the solution of Kukhtarev's equations (1979) must be retained,gratings due to higher harmonic beams must be included and, for the caseof the subharmonics, the new amplification mechanism must be used