Linear up-conversion of orbital angular momentum.

We experimentally demonstrated that infrared light imprinted with orbital angular momentum (OAM) was linearly converted into visible light using four-wave mixing (FWM) via a ladder-type configuration in 85Rb atoms. Simultaneously, we theoretically simulated this linear conversion process, and the theoretical analysis was in reasonable agreement with the experimental results. A large single-photon detuning process was used to reduce the absorption of the atoms to the up-converted light and to avoid pattern formation in the FWM process. The multi-mode image linear conversion process is important for applications including image communications, astrophysics, and quantum information.

[The effect of air purification on 10,000 degree clean room in supply rooms].

This article introduced that purifying equipments were installed in the major operating departments of supply rooms in hospital, and that experimental tests were done on the packing department. In statil state, the air humidity and the number of bacteria in the room after purification was obviously lower than that before purification (P < 0.01). In trending conditions, the main technical index on 10,000 degree clean rooms were examined, all of the results were up to the national standards.