title: Mid-infrared virtually imaged phased array spectrometer for rapid and broadband trace gas detection.
abstract: We present and characterize a two-dimensional (2D) imaging spectrometer based on a virtually imaged phased array (VIPA) disperser for rapid, high-resolution molecular detection using mid-infrared (MIR) frequency combs at 3.1 and 3.8 μm. We demonstrate detection of CH4 at 3.1 μm with >3750 resolution elements spanning >80 nm with ~600 MHz resolution in a <10 μs acquisition time. In addition to broadband detection, we also demonstrate rapid, time-resolved single-image detection by capturing dynamic concentration changes of CH4 at a rate of ~375 frames per second. Changes in absorption above the noise floor of 5×10(-4) are readily detected on the millisecond time scale, leading to important future applications such as real-time monitoring of trace gas concentrations and detection of reactive intermediates.
authors.affiliation: National Institute of Standards and Technology, Time & Frequency Division, Boulder, Colorado 80305, USA. lng@boulder.nist.gov
authors.forename: Lora
authors.initials: L
authors.lastname: Nugent-Glandorf
authors.forename: Tyler
authors.initials: T
authors.lastname: Neely
authors.forename: Florian
authors.initials: F
authors.lastname: Adler
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Fleisher
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Cossel
authors.forename: Bryce
authors.initials: B
authors.lastname: Bjork
authors.forename: Tim
authors.initials: T
authors.lastname: Dinneen
authors.forename: Jun
authors.initials: J
authors.lastname: Ye
authors.forename: Scott A
authors.initials: SA
authors.lastname: Diddams
mesh_terms: D008697:Methane / Q000032:analysis* / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000295:instrumentation*; D013997:Time Factors
chemical_list: D008697:Methane