We investigate the interaction of light and gas in strongly scattering nano- and macroporous media. Manufacturing and structural characterization of ${\mathrm{ZrO}}_2$, ${\mathrm{Al}}_2{\mathrm{O}}_3$ and ${\mathrm{TiO}}_2$ ceramics with different pore sizes, measurements of optical properties using photon time-of-flight spectroscopy, and high-resolution laser spectroscopy of ${\mathrm{O}}_2$ at 760 nm are reported. We show that extreme light scattering can be utilized to realize miniature spectroscopic gas cells. Path length enhancement factors up to 750 are reached (5.4 m path through gas for light transmitted through a 7 mm ${\mathrm{ZrO}}_2$ with 49% porosity and 115 nm pores).

• Received 31 January 2011

DOI:https://doi.org/10.1103/PhysRevLett.107.143901