Binary coded identification of industrial chemical vapors with an optofluidic nose

Abstract

An artificial nose system for the recognition and classification of gas-phase analytes and its application in identifying common industrial gases is reported. The sensing mechanism of the device comprises the measurement of infrared absorption of volatile analytes inside the hollow cores of optofluidic Bragg fibers. An array of six fibers is used, where each fiber targets a different region of the mid-infrared in the range of 2-14 μm with transmission bandwidths of about 1-3 μm. The quenching in the transmission of each fiber due to the presence of analyte molecules in the hollow core is measured separately and the cross response of the array allows the identification of virtually any volatile organic compound (VOC). The device was used for the identification of seven industrial VOC vapors with high selectivity using a standard blackbody source and an infrared detector. The array response is registered as a unique six digit binary code for each analyte by assigning a threshold value to the fiber transmissions. The developed prototype is a comprehensive and versatile artificial nose that is applicable to a wide range of analytes.

Towards an all-fiber system for detection and monitoring of ammonia

“…The quenching is important in establishing a threshold for measurements, where different wavelengths are used to target multiple gasses. 14…”

“…To this end, Hollow-Core Photonic Band Gap (HC-PBG) fibers have attracted huge attention by virtue of their promise to deliver a unique range of optical properties that are simply not possible with conventional solid core fiber types. [13][14][15][16] In HC-PBG fibers, over than 99% of the power in the optical mode is confined within the hollow core. This gives the provision of ultralow (a tunable) optical nonlinearity, excellent power handling capabilities, low latency, and even offers the prospect of ultralow losses, both at conventional wavelengths (e.g., around 1550 nm) and at longer wavelengths into the mid-IR where solid core silica fibers fail 17 .…”

Thermally drawn multifunctional fibers: Toward the next generation of information technology

“…Copyright 2013, American Chemical Society. Reproduced with permission 62 . Copyright 2016, The Optical Society; Integrated circuit fiber.…”

Optofluidic channels in anti-resonant hollow-core fibers using focused ion beam

“…Micro-channels in HCFs are particularly necessary when such fibers are fusion-spliced to solid-core fibers 7 , to make compact and robust sensors, because splicing prevents fluid diffusion between the fiber core and external environment. Such diffusion, however, is essential for many applications in fluid-filled 5,8,9 or liquid-filled [10][11][12] HCF experiments, where interaction between fluid and light beam is required. The creation of access channels into the core that can survive splicing and does not increase the insertion loss of the fiber by light leaking out of the core, is thus of prime importance for the use of HCFs in sensing applications as well as towards development of compact gas-based fiber lasers using for the ultra-violet or mid-infrared spectral range [13][14][15] The reported lowest loss induced by a micro-channel in an HCF is ~0.35 dB for a single hole with a diameter of ~500 nm, drilled with femtosecond laser 4 .…”