The researcher Diederik Wiersma, from the European laboratory of nonlinear spectroscopy in Florence, presented a material that emits laser rays when the temperature drops from a certain point. To achieve this he mixed liquid crystals tinted to the glass. Subsequently, the material was subjected to the action of the green light laser and when the temperature of 42.5 °C dropped, the material emitted laser rays.
It seems that when the liquid crystal is cooled, so the photons remain trapped in the material for a long time and the electrons of the dye molecules are more likely to be excited. When the excited electrons lose this energy, they release light. This material could be used in temperature sensors and temperature sensitive devices.