Proposal for all-optical controllable switch using dipole induced transparency (DIT)

Proposal for all-optical controllable double state switch using dipole induced transparency (DIT)

“…After applying the control field of E c2 nanocrystal levels |a 0 >, |a + > and |a ->, known as dressed states, are obtained. Dressed states are given by the following relations [6][7][8][9][10][11][12][13][14][15][16][17]. …”

“…Then the input field transmits from original waveguide into another through the cavity, and the switching process is completed. The Hamiltonian of the 4-level system, by using Rotating wave approximation, can be written as [9,13] : …”

“…Where, we have assumed that the optical signal is very weak to transit electrons from the bottom state to the upper state and the control field is sufficiently far from resonant, so population transition by control field is neglected too [1,9].…”

“…So, we have used DIT based system, where perpendicular applied control field to the cavity is strong enough. Therefore we can get strong Purcell regime (g 2 /κγ >1), where γ is the QD decay into modes other than the cavity mode, κ is the cavity field decay rate and g is the coupling between the cavity and the QD [8,9]. Another important advantage of the proposed switch is controllability by the control field amplitude, shown in Fig.…”

“…You can see, if we dope four level nanocrystal in PC cavity, multi state switch is realizable by two fields. Basic principles of EIT and applications of this phenomenon has been discussed by distinguished scientists [7][8][9][10][11][12][13]. For description of the quantum optical nature of light propagation through EIT media including 3-level atoms density matrix method incorporating classical light and quantum mechanical particles are needed.…”