  We show two channel electromagnetically induced transparency (EIT) spectra at
various optical power. The two channels are coupling field and probe field
absorption. It is shown that EIT width and intensity increases linearly with
pump power. A density matrix calculation is used to determine nature of EIT
spectra induced by optical field. It has been observed that EIT occurs in cases
when coupling laser is at fixed frequency while probe laser frequency is
scanned, when coupling laser is frequency scanned and probe is at fixed
frequency.
