title: Ultrasensitive photoacoustic sensor based on quantum cascade laser spectroscopy.
abstract: The paper focuses on development of ultra-sonic detection system based on laser photoacoustic spectroscopic technique and processing of signal for detection of very low quantity chemicals, explosive materials, and mixtures of these hazardous molecules. The detection system has been developed for the first time with specially designed one side open photo-acoustic cell having high quality factor. Explosive and Hazardous materials like RDX, DNT, PETN, Gun Powder, TATP (Tri acetone tri-peroxide) and their simulants like Acetone were detected in 7 to 9μm wavelength band. Lock in amplifier electronic instrument was used for the detection of hazardous chemicals and mixture of explosives in very low quantity. Detection limit of the photoacoustic ultrasonic sensor was also carried out of powder, liquid and adsorbed on surfaces.
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India.
authors.forename: Surya
authors.initials: S
authors.lastname: Gautam
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India.
authors.forename: Subodh
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India.
authors.forename: Hari B
authors.initials: HB
authors.lastname: Srivastava
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India.
authors.forename: Surya N
authors.initials: SN
authors.lastname: Thakur
authors.affiliation: Laser Science and Technology Centre, DRDO, Delhi 110054, India. Electronic address: ramehsharma@lastec.drdo.in.
authors.forename: Ramesh C
authors.initials: RC
authors.lastname: Sharma
keywords: COMSOL software; I R spectroscopy; Lock-in amplifier card; Mixture of explosive trace detection; Photoacoustic sensor; Quantum cascade laser spectroscopy; Resonant photoacoustic cell one side open