Ultra-low threshold optically pumped random laser emission behavior of highly oriented pyrolytic graphite

• This paper report random laser emission behavior of highly oriented pyrolytic graphite (HOPG).
• The optical pumped laser emission spectra were analyzed.
• The theoretical model accounts for the lasing behavior in HOPG was proposed.

Graphite is a semimetal and thus has no bandgap; photoluminescence is not expected from relaxed charge carriers. Here, however, an ultralow threshold optically pumped random lasing behavior in highly oriented pyrolytic graphite (HOPG) was observed under 488 nm Ar+ laser excitation at room temperature. In addition, this lasing behavior differs from the conventional random lasing process, i.e., the emission exhibits an ultra-low lasing threshold and a linear dependence on the laser excitation intensity in a low power range, and it saturates at high excitation densities. The theoretical model which accounts for the optically pumped random lasing behavior in HOPG has been proposed.

Ultra-low threshold optically pumped random laser emission behavior of highly oriented pyrolytic graphite. Figure optionsDownload as PowerPoint slide