Band-edge photorefractive effect in semiconductors

Afshin Partovi, Alan Kost, Elsa M. Garmire, George C. Valley, Marvin B. Klein

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


We report here for the first time, two-beam coupling energy transfer using the Franz-Keldysh electrorefractive effect in photorefractive semiconductors. A large beam coupling gain coefficient (Γ=2.8 cm-1) exceeding the absorption coefficient (α=2.0 cm-1) is obtained in undoped semi-insulating GaAs using the new photorefractive process. The new photorefractive process differs from conventional photorefractivity in that the direction of energy transfer is dictated by the direction of an externally applied electric field. Using a moving grating technique and combining the electrorefractive grating with the conventional electro-optic grating, a very large gain Γ=16.3 cm-1 (α=3 cm-1, crystal length l=4mm) resulting in net amplification by more than a factor of 200 has been demonstrated.

Original languageEnglish (US)
Pages (from-to)1089-1091
Number of pages3
JournalApplied Physics Letters
Issue number12
StatePublished - 1990
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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