Mar 31, 2020
Recently, Shawn-YuLin, a physicist at Rensselaer Institute of technology, published a new paper in the Journal of natural science report, saying that scientists have now found a material whose heated luminous intensity seems to exceed the radiation limit of blackbody. This new material can be used in energy collection, military infrared object tracking and recognition, atmospheric chemical spectroscopy research, laser and other fields.
In the early 19th century, Max Planck, a German physicist, used mathematical methods to describe the law of radiation and assumed that energy can only exist in discrete values, thus entering the quantum era. Max was also named the founder of quantum mechanics. Since the end of the 19th century, we have known that all materials emit light in a predictable wavelength range when heated. According to Planck's law, no object in the universe can emit more radiation than a blackbody. Blackbody is an ideal object. It can absorb all the electromagnetic radiation from outside without any reflection and transmission. With the rise of temperature, the electromagnetic wave and light emitted by blackbody is called blackbody radiation.
Shawn Yulin found that a new material violates the limitations of Planck's law. It is a three-dimensional photonic crystal based on tungsten (similar to diamond crystal in structure). When heated to 600k, its luminous intensity is 8 times of the blackbody standard, and the material structure shows a radiation peak of about 1.7 μ M. The new materials can emit similar coherent light produced by lasers or light-emitting diodes (LEDs), but they do not need complex and expensive semiconductor structures.
Shawn Yulin said that in fact, this does not violate Planck's law, but is a new way to generate heat. Although theory cannot fully explain this phenomenon, scientists assume that the shift between layers of a photonic crystal allows light to shoot out of the internal space of the crystal, and the light emitted bounces back and forth in the crystal structure, thus changing the performance of the light. The behavior is almost like that of an artificial laser material.