title: 3D-printed miniature gas cell for photoacoustic spectroscopy of trace gases.
abstract: A new methodology for the development of miniature photoacoustic trace gas sensors using 3D printing is presented. A near-infrared distributed feedback (DFB) laser is used together with a polymer-based gas cell, off-the-shelf fiber optic collimators, and a microelectromechanical system (MEMS) microphone to measure acetylene at 1532.83 nm. The resonance behavior of the miniature gas cell is analyzed using a theoretical and experimental approach, with a measured resonance frequency of 15.25 kHz and a Q-factor of 15. A minimum normalized noise equivalent absorption of 4.5×10(-9)  W cm(-1) Hz(-1/2) is shown together with a 3σ detection limit of 750 parts per billion (ppb) for signal averaging times of 35 s. The fiber-coupled delivery and miniature cost-effective cell design allows for use in multipoint and remote detection applications.
authors.forename: Ralf
authors.initials: R
authors.lastname: Bauer
authors.forename: George
authors.initials: G
authors.lastname: Stewart
authors.forename: Walter
authors.initials: W
authors.lastname: Johnstone
authors.forename: Euan
authors.initials: E
authors.lastname: Boyd
authors.forename: Michael
authors.initials: M
authors.lastname: Lengden