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United States Patent

US Patent 8309929: Tunable photonic cavities for in-situ…

US 8309929  ·  granted 2012-11-13

Abstract

Compact tunable optical cavities are provided for in-situ NIR spectroscopy. MEMS-tunable VCSEL platforms represents a solid foundation for a new class of compact, sensitive and fiber compatible sensors for fieldable, real-time, multiplexed gas detection systems. Detection limits for gases with NIR cross-sections such as O.sub.2, CH.sub.4, CO.sub.x and NO.sub.x have been predicted to approximately span from 10.sup.ths to 10s of parts per million. Exemplary oxygen detection design and a process for 760 nm continuously tunable VCSELS is provided. This technology enables in-situ self-calibrating platforms with adaptive monitoring by exploiting Photonic FPGAs.

Patent Number 8309929
Title Tunable photonic cavities for in-situ spectroscopic trace gas detection
Granted 2012-11-13
CPC Classification G01J 5/02
Number of Claims 19

Abstract

Compact tunable optical cavities are provided for in-situ NIR spectroscopy. MEMS-tunable VCSEL platforms represents a solid foundation for a new class of compact, sensitive and fiber compatible sensors for fieldable, real-time, multiplexed gas detection systems. Detection limits for gases with NIR cross-sections such as O.sub.2, CH.sub.4, CO.sub.x and NO.sub.x have been predicted to approximately span from 10.sup.ths to 10s of parts per million. Exemplary oxygen detection design and a process for 760 nm continuously tunable VCSELS is provided. This technology enables in-situ self-calibrating platforms with adaptive monitoring by exploiting Photonic FPGAs.

Claim 1

A method for detecting a gas, comprising: electrically driving above a lasing threshold an extended cavity vertical cavity surface emitting laser to produce laser emission light ata wavelength and a power, wherein said laser includes a microelectromechanically tunable optical cavity; placing said laser in a position of interest; and tuning said optical cavity to produce a second wavelength that corresponds to an absorptionwavelength of a gas of interest, wherein if said gas enters said extended cavity said power will be reduced, wherein said cavity is functionalized with a gas-sensitive coating.

Claims

19 total

A method for detecting a gas, comprising: electrically driving above a lasing threshold an extended cavity vertical cavity surface emitting laser to produce laser emission light ata wavelength and a power, wherein said laser includes a microelectromechanically tunable optical cavity; placing said laser in a position of interest; and tuning said optical cavity to produce a second wavelength that corresponds to an absorptionwavelength of a gas of interest, wherein if said gas enters said extended cavity said power will be reduced, wherein said cavity is functionalized with a gas-sensitive coating.