US 6,982,426 B1
Nitric oxide sensor and method
Robert P. Lucht, West Lafayette, Ind. (US); Thomas N. Anderson, West Lafayette, Ind. (US); Sherif F. Hanna, College Station, Tex. (US); Rodolfo Barron-Jimenez, College Station, Tex. (US); Thomas Walther, Darmstadt (Germany); Sukesh Roy, Dayton, Ohio (US); Michael S. Brown, Dayton, Ohio (US); James R. Gord, Dayton, Ohio (US); and Jerald A. Caton, College Station, Tex. (US)
Assigned to The United States of America as represented by the Secretary of the Air Force, Washington, D.C. (US)
Filed on Aug. 06, 2004, as Appl. No. 10/914,782.
Claims priority of provisional application 60/493564, filed on Aug. 07, 2003.
Int. Cl. G01J 1/42 (2006.01)
U.S. Cl. 250—373 2 Claims
OG exemplary drawing
 
1. A nitric oxide sensor, comprising:
a 532-nm diode pumped intracavity frequency doubled Nd:YAG laser;
a 395-nm external cavity diode laser including driver electronics;
a dichroic mirror for overlapping the output of said external cavity diode laser and said Nd:YAG laser;
a beta-barium-borate crystal including a focusing lens ahead of said crystal and a collimating lens after said crystal, said crystal being positioned to receive the output from said dichroic mirror and to generate a sum-frequency-mixed radiation beam at 227 nm;
a 50—50 beam splitter for splitting said radiation beam from said beta-barium-borate crystal into a reference beam and a signal beam;
a reference photomultiplier tube for generating a reference output from said reference beam;
at least one mirror for passing said signal beam through a medium of interest;
a signal photomultiplier tube for generating a signal output from said signal beam; said signal photomultiplier tube receiving said signal beam after passage through the medium of interest; and,
a microprocessor for comparing said signal output and said reference output to determine the level of nitric oxide within the medium of interest.