Finite size effect of one-dimensional thermal radiation

Abstract

The size effect of one-dimensional thermal radiation is investigated as a function of length and temperature. When the length of the body becomes small, the maximum wavelength of the thermal radiation is on the order of the size, so the spectrum of the thermal radiation becomes different from that of one-dimensional blackbody radiation. We calculate the energy density by considering the dimension of the length. The thermal radiation can be approximated by Wien's law in highfrequency range when the size becomes small. The energy density is shown to be a function of length at constant temperature. The energy density is also shown to be a function of temperature at constant length.