Abstract:According to the dipole transition selection rules and by choosing proper transition channels, it is found that the inverted Y-type four-level scheme can be classified into nine different 2nd-order subschemes when using corresponding laser fields, and they can be further classified into eighty 3rd-order subschemes in detail according to different exciting intensities that are applied in different channels. In this paper, the structure multiformity of inverted Y-type four-level scheme is discussed and the de...