Magnetic Control of Polarization Switching

Mickey McDonald

Yang Liu, Xiang-an Yan, Ze-kai Yu +5 more

We report a simplified all-optical scheme that achieves dynamical switching between electromagnetically induced transparency (EIT) and absorption (EIA) in a [Formula: see text]-type atomic system using only two lasers. The switch is controlled via the polarization ([Formula: see text]) and propagation direction of the optical fields. By applying a weak magnetic field, we spectroscopically resolve the degenerate transition into Zeeman-split subsystems and identify an effective N-type pathway as the physical origin of the switching. Theoretical analysis based on dressed-state perturbation theory reveals that the EIT–EIA transition results from constructive quantum interference between secondary dressed states. The scheme also generates tunable dual transparency windows, enabling potential applications in multi-channel signal routing and polarization-controlled slow-light devices.

Oliver Brandel, Olaf Wetzstein, T. May +3 more

Superconducting radiation sensors are of particular interest for imaging applications in the sub-mm wavelength band because of their extraordinary sensitivity. The rising number of sensors integrated in one array entails the requirement of multiplexing techniques in order to reduce the number of wires leading into the cryogenic stage and thus reduce the thermal losses. One kind of promising code division multiplexing technique is based on a current steering switch (CSS), which is composed of two identical superconducting quantum interference devices (SQUIDs) in parallel current paths. One of them is switched from the superconducting into the normal state controlled by the applied magnetic flux. In this way the signal path can be altered and they can act as a polarity switch for analogue signals. We pursue this concept to use rapid single flux quantum (RSFQ) electronics for controlling these switches. As a first step, the SQUIDs of the CSS are inductively coupled to the storing loops of two delay flip flops (DFFs). Thus, one is able to toggle the polarity of the analogue switch by controlling the state of the DFF by RSFQ control signals. The results of simulations and measurements and also margin analyses are discussed.

Mark F. Johnson, Chris N. Pannell

Hans Paetz gen. Schieck

R. Karimi, Saeid Batebi, HAMID RAHIMPOUR SOLEIMANI

this paper studied the magnetic field effect on optical properties in a closed lambda-type three level atomic system. Two circularly polarized components are interacted separately by two transitions of this medium. By numerically solving the density matrix equations for this system, it is demonstrated that the optical properties of system, such as absorption, dispersion and lasing, can be controlled via switching on and off an external magnetic field. The proposed scheme may have applications in the design of magneto-optic switching devices. Also the time dependent behavior of the absorption curve in the presence of magnetic field and incoherent pumping field investigated.