Different mechanism to generate and reconfigure circularly polarized light
Spin-polarized or circularly polarized light is of vital importance in fundamental and applied sciences. It is typically obtained using either chiral light sources (structural chirality) or polarization conversion devices such as quarter wave plates.
In our recent work, we found a new mechanism based on near-field coupling between antennas at unequal temperatures.
Interestingly, with this mechanism, the polarization state of light can be reconfigured by simply interchanging the temperatures of the antennas.
Solid-state thermal refrigeration scheme using laser light and nonlinear four-wave mixing
Traditional thermoelectric coolers used for electronics heat-management can cool devices upto T~170K but cannot go below that. To go below this temperature limit, the only other solid-state approach without using cryogenics and moving parts is that of laser cooling of solids containing rare earth ions. With that approach, temperatures as low as T~90K have been realized [See Melgaard et al]. To go further below this attainable temperature, there is an incentive to think outside the box and create new solid-state refrigeration devices. Also, given the rapid miniaturization of all technologies, new refrigeration approaches can be quite useful in the near future for micro- and nanoscale heat management,
In this work, we propose a new method which uses resonantly enhanced nonlinear mixing of laser light with near-field thermal radiation. This method extracts thermal energy from a solid supporting surface polaritons at its interface. With this method, in principle, highly efficient thermal refrigeration can be performed using nanophotonic engineering and very low temperatures of T~10K can be realized starting from the device at ambient temperature.