[摘要]：We present the transformation of electromagnetically induced transparency (EIT) into narrow enhanced absorption with an on-resonant standing-wave coupling field in the 5S(1/2)-5P(1/2) transition of the Lambda-type system of Rb-87 atoms. When a coupling laser field was changed from a travelling-wave to a standing-wave that was made by adding a counter-propagating L-C laser, the transmittance spectrum of the L-P laser transformed the typical EIT into dramatically enhanced absorption, and a Bragg reflection signal was generated by the periodic modulation of atomic absorption. The reflected probe laser corresponding to a Bragg reflection was measured to be approximately 11.5% of the power of the incident probe laser. We analyzed the enhanced absorption signal and Bragg reflection spectrum as a function of the power and frequency detuning of the coupling laser. (C) 2010 Optical Society of America
