title: Laser absorption spectroscopy of oxygen confined in highly porous hollow sphere xerogel.
abstract: An Al2O3 xerogel with a distinctive microstructure is studied for the application of laser absorption spectroscopy of oxygen. The xerogel has an exceptionally high porosity (up to 88%) and a large pore size (up to 3.6 µm). Using the method of gas-in-scattering media absorption spectroscopy (GASMAS), a long optical path length (about 3.5m) and high enhancement factor (over 300 times) are achieved as the result of extremely strong multiple-scattering when the light is transmitted through the air-filled, hollow-sphere alumina xerogel. We investigate how the micro-physical feature influences the optical property. As part of the optical sensing system, the material's gas exchange dynamics are also experimentally studied.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Gabriel
authors.initials: G
authors.lastname: Somesfalean
authors.forename: Sailing
authors.initials: S
authors.lastname: He
mesh_terms: D065966:Absorption, Physicochemical; D005782:Gels / Q000737:chemistry*; D007834:Lasers; D010092:Oximetry / Q000295:instrumentation / Q000379:methods*; D010100:Oxygen / Q000032:analysis* / Q000737:chemistry*; D016062:Porosity; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*
chemical_list: D005782:Gels; D010100:Oxygen