An atomic object confined in a particular region of an atomic object confinement apparatus is cooled using an S-to-P-to-D EIT cooling operation. A controller associated with the atomic object confinement apparatus controls first and second manipulation sources to respectively provide first and second manipulation signals to the particular region. The first manipulation signal is characterized by a first wavelength corresponding to a transition between an S manifold and a P manifold of a first component of the atomic object and detuned from the S-to-P transition by a first detuning. The second manipulation signal is characterized by a second wavelength corresponding to a transition between the P manifold and a D manifold of the first component and detuned from the P-to-D transition by a second detuning. The first and second detunings selected to establish a dark state associated with a two-photon transition between the S manifold and the D manifold.

An atomic object confined in a particular region of an atomic object confinement apparatus is cooled using an S-to-P-to-D EIT cooling operation. A controller associated with the atomic object confinement apparatus controls first and second manipulation sources to respectively provide first and second manipulation signals to the particular region. The first manipulation signal is characterized by a first wavelength corresponding to a transition between an S manifold and a P manifold of a first component of the atomic object and detuned from the S-to-P transition by a first detuning. The second manipulation signal is characterized by a second wavelength corresponding to a transition between the P manifold and a D manifold of the first component and detuned from the P-to-D transition by a second detuning. The first and second detunings selected to establish a dark state associated with a two-photon transition between the S manifold and the D manifold.

Passive cooling article (120) includes a plurality of first elements (122) defining a high absorbance in the atmospheric window wavelength range and defining high average reflectance in the solar wavelength range and a plurality of second elements (124) defining a low absorbance in the atmospheric window wavelength range and defining high average reflectance in the solar wavelength range, wherein the plurality of first (122) and second (124) elements are interspersed to form a major structure having a first major surface (130) comprising the first element outer surfaces (126) and the second element outer surfaces (128), wherein the first element outer surfaces (126) face a first direction toward a first end region (136) of the major structure (130) and the second element outer surfaces (128) face a second direction toward a second end region (136) of the major structure. The article (120) may be applied to a substrate (104), for example, on a generally vertical surface of a vehicle or stationary structure.

Passive radiative cooling structures and apparatus manufactured with such cooling structures conserve energy needs. A flexible film transparent to visible light incorporates particles at a volume percentage larger than 25% so as to absorb and emit infrared radiation at wavelengths where Earth's atmosphere is transparent. Another film transparent to visible light is thin and flexible and configured to absorb and emit infrared radiation at wavelengths where Earth's atmosphere is transparent, wherein etchings or depositions are present on one or both surfaces. A high efficiency cooling structure has an emissive layer sandwiched between a waveguide layer and a thermal conductive layer. A solar cell panel is covered by a transparent passive radiative cooling film. A container housing an active cooling unit incorporates passive radiative cooling structures on one or more exterior surfaces.

The present invention relates to a technique of cooling a temperature on the surface or under a material by emitting heat under a radiative cooling device to the outside while minimizing the absorption of light in a solar spectrum by forming a paint coating layer with excellent radiative cooling performance on various surfaces. A radiative cooling device according to an embodiment of the present invention may include a paint coating layer formed by coating or dyeing on various surfaces a paint solution mixed with nano or microparticles of which a particle size and a composition are determined in consideration of infrared emissivity and reflectance to incident sunlight in a wavelength range corresponding to a sky window and a binder mechanically connecting the surfaces of the nano or microparticles in a solvent.

Embodiments described herein generally relate a multi-mode heat transfer system. The heat transfer system includes an emitter device. The emitter device includes an inner core, a composite material pattern, and a surface coating pattern. The inner core is surrounded by an outer core having a thickness and an outer surface. The composite material pattern extends through at least a portion of the outer surface and at least a portion of the thickness of the outer core and is thermally coupled to the inner core. The surface coating pattern is on the outer surface and is changeable between a low emissivity state and a high emissivity state based on a surface temperature of the emitter device. In the low emissivity state, the emitter device transmits an omni-directional radiation and, in the high emissivity state, the emitter device transmits a focused radiation via the composite material pattern.

A composite cooling film including non-fluorinated organic polymeric layer, a metal layer disposed inwardly of the non-fluorinated organic polymeric layer, and an antisoiling, ultraviolet-absorbing hardcoat layer that is disposed outwardly of the non-fluorinated organic polymeric layer.

In most buildings energy for space heating and cooling can be used to maintain the thermal comfort of the building's human occupants by maintaining the interior air temperature at a set point. If one could maintain the human occupant's thermal comfort while decreasing the heating or increasing the cooling set point, energy savings are possible. Many embodiments implement methods and systems of tunable emissivity surfaces in improving building efficiency. Several embodiment implement tuning the thermal emissivity of interior building surfaces at long-wave infrared wavelengths to maintain thermal comfort.

Polymer-based selective radiative cooling structures are provided which include a selectively emissive layer of a polymer or a polymer matrix composite material. Exemplary selective radiative cooling structures are in the form of a sheet, film or coating. Also provided are methods for removing heat from a body by selective thermal radiation using polymer-based selective radiative cooling structures.

The present invention provides a colored radiative cooler based on a Tamm structure, including a substrate on which metal film and dielectric layers A to G are sequentially provided from bottom to top, where the Tamm structure is formed from the metal film and the dielectric layers A to D; a distributed Bragg reflector is formed from the dielectric layers A to D; and a selective emitter is formed from the dielectric layers E to G. Compared to the conventional radiative cooler, the colored radiative cooler not only has better cooling performance, but it has a wide applications in many aspects such as aesthetics and decoration.