A photo-thermal interferometric spectroscopy system is disclosed that provides information about a chemical at a remote location. A first light source assembly is included that emits a first beam. The first beam has one or more wavelengths that interact with the chemical and change a refractive index of the chemical. A second laser produces a second beam. The second beam interacts with the chemical resulting in a third beam with a phase change that corresponds with the change of the refractive index of the chemical. A detector system is positioned remote from the chemical to receive at least a portion of the third beam. An adaptive optics system at least partially compensates the light beam degradation caused by atmospheric turbulence. A focusing system is used to bring together the light passed through the chemical; the focusing system includes a multimode fiber for the light collection, The detector system provides information on a phase change in the third beam relative to the second beam that is indicative of at least one of, absorption spectrum and concentration of the chemical.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 10/947,640 filed Jan. 13, 2005 now U.S. Pat. No. 7,277,178 and Ser. No. 11/561,966 filed Nov. 21, 2006 now U.S. Pat. No. 7,426,035, both of which applications are fully incorporated herein by reference. This application is a continuation-in-part of U.S. Ser. No. 10/669/130 filed Sep. 22, 2003 now U.S. Pat. No. 7,327,913 and Ser. No. 11/672,372 filed Feb. 7, 2007.
