Low-cost Formaldehyde Sensor Evaluation and Calibration in a Controlled Environment

Autor: Arnab Chattopadhyay, Andres Huertas, Andrew Rebeiro-Hargrave, Pak Lun Fung, Samu Varjonen, Tuomas Hieta, Sasu Tarkoma, Tuukka Petaja

Formaldehyde is a carcinogenic indoor air pollutant emitted from common wood-based materials. Low-cost sensing of formaldehyde is difficult due to inaccuracies in measuring low concentrations and susceptibility of sensors to changing indoor environme

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5574c31fe0fb72311a6820ce6161adff
http://hdl.handle.net/10138/345363

Cantilever-enhanced Photoacoustic Detector for Light-absorbing Aerosols

Autor: Juho Karhu, Joel Kuula, Aki Virkkula, Hilkka Timonen, Markku Vainio, Tuomas Hieta

Publikováno v: University of Helsinki

We present here the first application of cantilever-enhanced photoacoustic spectroscopy for aerosol absorption measurements. A noise equivalent absorption of 1.3x10-10 cm-1 (one standard deviation) is reached with 20 s sampling time.

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ad9aadca64355a1b5f305c70a6d57504
https://doi.org/10.1364/lacsea.2022.lw4d.5

Optical power detector with broad spectral coverage, high detectivity, and large dynamic range

Autor: Jussi Rossi, Juho Uotila, Sucheta Sharma, Tuomas Hieta, Toni Laurila, Roland Teissier, Alexei Baranov, Erkki Ikonen, Markku Vainio

Publikováno v: Rossi, J, Uotila, J, Sharma, S, Hieta, T, Laurila, T, Teissier, R, Baranov, A, Ikonen, E & Vainio, M 2022, ' Optical power detector with broad spectral coverage, high detectivity, and large dynamic range ', Optics Letters, vol. 47, no. 7, pp. 1689-1692 . https://doi.org/10.1364/OL.455191

Optical power measurements are needed in practically all technologies based on light. Here, we report a general-purpose optical power detector based on the photoacoustic effect. Optical power incident on the detector’s black absorber produces an ac

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0671bbd45ed6867e708d0e9e80004cc4
https://trepo.tuni.fi/handle/10024/138757

LED-Based Photoacoustic NO2Sensor with a Sub-ppb Detection Limit

Autor: Markku Vainio, Erkki Ikonen, Juho Karhu, Tuomas Hieta, Farshid Manoocheri

Publikováno v: Karhu, J, Hieta, T, Manoocheri, F, Vainio, M & Ikonen, E 2021, ' LED-Based Photoacoustic NO 2 Sensor with a Sub-ppb Detection Limit ', ACS Sensors, vol. 6, no. 9, pp. 3303–3307 . https://doi.org/10.1021/acssensors.1c01073

Funding Information: The work was supported by the Academy of Finland (Project Numbers 326444 and 314364) and by the Academy of Finland’s Flagship Programme, Photonics Research and Innovation (PREIN), Decision Number: 320167. Publisher Copyright: �

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::013e192695b951341bc499dbb84dc6b1
https://aaltodoc.aalto.fi/handle/123456789/110313

Sensitive Multi-species Gas Sensing with Supercontinuum-based Photoacoustic Spectroscopy

Autor: Tommi Mikkonen, Tuomas Hieta, Goëry Genty, Juha Toivonen

Publikováno v: 2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC).

Photoacoustic spectroscopy (PAS) is a sensitive gas sensing technique widely used for single species detection in small sample volumes [1] . The operation principle of PAS relies on the conversion of electromagnetic radiation into acoustic waves by t

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::c5ed1d95294c9558ca3e9cf4ce2f606b
https://doi.org/10.1109/cleo/europe-eqec52157.2021.9542658