Contact Dr Jane Hodgkinson
- Tel: +44 (0) 1234 758325
- Email: j.hodgkinson@cranfield.ac.uk
- ORCID
Areas of expertise
- Instrumentation, Sensors and Measurement Science
- Sensor Technologies
Background
Dr Jane Hodgkinson joined Cranfield University from the natural gas industry, where she was responsible for developing and testing new sensing technologies, particularly optical sensors for gas leaks. At Cranfield, Jane established gas detection laboratories and now leads this activity within the Centre for Engineering Photonics. The centre has provided an intellectually stimulating and supportive environment with a great deal of cross-fertilisation of ideas, so that we can borrow new techniques developed for one measurand and apply them to another.
Jane obtained her PhD in 1998 from the Optoelectronics Research Centre at the University of Southampton, working in a collaboration with United Utilities on photoacoustic and photothermal detection of trace chemicals in water. She gained her first degree in Natural Sciences (Physics, 1st class hons) from Cambridge University in 1989.
Jane chairs the Gas Analysis and Sensing Group (www.gasg.info), a multidiscipinary, independent forum for discussion of gas and airborne particle sensing and analysis, which brings together manufacturers of instruments, sensors and components, academic research, major users and independent consultants. The organisation runs in the manner of a scientific society, hosting 3 topical meetings per year.
Research opportunities
Jane is working to develop advanced tools for optical gas detection with improved levels of robustness and lower complexity, aiming to move this important technique from the laboratory and into the field. This includes instruments based on tunable diode laser spectroscopy (TDLS) in the near and mid infrared regions of the spectrum, plus lower cost non-dispersive sensors in the mid-IR and UV.
Current activities
Below is a selection of some of our research projects. Most of them have been performed in collaboration with some amazing scientists and engineers from different fields, based in universities and industry - see list of funders and collaborators.
- Use of diffuse optical reflectors in optical gas cells for TDLS to improve field robustness, ease of alignment, and a reduction in structured interference fringes, whih can cause performance limitations. This work included a study of the effects of laser speckle - a form of random interference experienced when using optical diffusers - and the use of intergrating spheres as potential multipass cells with extended optical pathlengths.
- Novel, compact pathlengths for low-cost NDIR using gold-coated, injection moulded optics. A non-dispersive infrared (NDIR) containing Jane's patented optics design was developed in collaboration by Alphasense Ltd and successfully commercialised by the company, for use in carbon dioxide sensing and later extended to methane.
- Non-dispersive ultra-violet measurement of formaldehyde gas, a volatile organic compound (VOC) found indoor environments.
- Ultra-low volume (a few mL) optical gas cells for use in the mid-IR region. The low volume allows two different modes of use. The first is to enable the use of very low (e.g 5mL/minute) flow rates in headspace sampling of small (a few mL) biological samples, such as faeces, with the aim of diagnosing gastrointestinal diseases. The idea is that low flow rates increase the headspace concentrations of volatile organic compounds, making them easier to deetct at parts per billion (ppb) levels. The second mode of use is that, for higher gas sampling flow rates, a fast sensor response can be achieved. This is important for example in breath analysis in order to make time-resolved breath-by-breath measurements of target gases, in the manner of capnography.
- Methods to improve the conspicuity of survival suits in marine search and rescue. The suits are designed to be worn by helicopter pilots when flying over the sea, in case there is an accident and survivors need to be rescued. Search and rescue can be considered an optical detection process performed by highly trained professionals, which is augmented by advanced lighting and imaging technology and the use of high-performance materials. Survival suits include retroreflective surfaces that appear bright when illuminated by the powerful searchlights mounted on search and rescue aircraft. This research also developed new methods to test novel suit designs in real-world scenarios in marine environments, and the effects of using such bright materials on pilot distraction within the cockpit.
- A new instrument to measure changes in the spectroscopic signature of bitumen in asphalt, which occur as a result of the ageing process. These signatures occur around 6µm in the mid-IR, which is a challenging region in which to work because of the high density of spectral absorption lines caused by atmospheric water vapour.
Clients
Funding for this work has been provided by:
Engineering and Physical Sciences Research Council (EPSRC)
Natural Environment Research Council (NERC)
The Royal Society
Technology Strategy Board (TSB)
Alphasense Ltd
Geotechnical Instruments Ltd
AWE Plc
Cascade Technologies Ltd.
Publications
Articles In Journals
- Francis D, Hodgkinson J & Tatam RP. (2024). Long-wave infrared pulsed external-cavity QCL spectrometer using a hollow waveguide gas cell. Optics Express, 32(10)
- Davis NM, Francis D, Hodgkinson J & Tatam RP. (2023). Compact methane sensor using an integrating sphere and interband cascade laser at 3313 nm. Sensors and Actuators B: Chemical, 389(August)
- Bremner J, Kissinger T, Hodgkinson J & Tatam RP. (2021). Fibre-coupled, multiplexed methane detection using range-resolved interferometry. Journal of Physics: Photonics, 3(2)
- Bergin S, Hodgkinson J, Francis D & Tatam RP. (2020). Ratiometric pathlength calibration of integrating sphere-based absorption cells. Optics Express, 28(13)
- Lourenço C, Bergin S, Hodgkinson J, Francis D, Staines SE, .... (2020). Instrumentation for quantitative analysis of volatile compounds emission at elevated temperatures. Part 2: Analysis of carbon fibre reinforced epoxy composite. Scientific Reports, 10(1)
- Lourenço C, Bergin S, Hodgkinson J, Francis D, Staines SE, .... (2020). Instrumentation for quantitative analysis of volatile compounds emission at elevated temperatures. Part 1: Design and implementation. Scientific Reports, 10(1)
- Nixon J, Hodgkinson J & Bennett C. (2020). Modified immersion suits for helicopter aircrew: evidence for improved conspicuity from sea trials. Safety Science, 130
- Davis NM, Lynch SF, Gates JC, Hodgkinson J, Smith PGR, .... (2019). Spectroscopic gas detection using a Bragg grating - stabilized external cavity laser, custom written in planar integrated silica-on-silicon. Optics Express, 27(20)
- Davenport JJ, Hodgkinson J, Saffell JR & Tatam RP. (2018). Non-dispersive ultra-violet spectroscopic detection of formaldehyde gas for indoor environments. IEEE Sensors Journal, 18(6)
- Asmari A, Hodgkinson J, Chehura E, Staines SE & Tatam RP. (2017). All-electronic frequency stabilization of a DFB laser diode. Optics Express, 25(10)
- Francis D, Hodgkinson J, Livingstone B, Black P & Tatam RP. (2016). Low-volume, fast response-time hollow silica waveguide gas cells for mid-IR spectroscopy. Applied Optics, 55(25)
- Bergin S, Hodgkinson J, Francis D & Tatam RP. (2016). Integrating cavity based gas cells: a multibeam compensation scheme for pathlength variation. Optics Express, 24(12)
- Francis D, Masiyano D, Hodgkinson J & Tatam RP. (2015). A mechanically stable laser diode speckle interferometer for surface contouring and displacement measurement. Measurement Science and Technology, 26(5)
- Davenport J, Hodgkinson J, Saffell JR & Tatam RP. (2015). A measurement strategy for non-dispersive ultra-violet detection of formaldehyde in indoor air: Spectral analysis and interferent gases. Measurement Science and Technology, 27(1)
- Davenport J, Hodgkinson J, Saffell JR & Tatam RP. (2015). Noise analysis for CCD-based ultraviolet and visible spectrophotometry. Applied Optics, 54(27)
- Chowdhury SA, Correia RN, Francis D, Brooks SJ, Jones BJS, .... (2015). An optical fiber hydrogen sensor using a palladium-coated ball lens. Journal of Lightwave Technology, 33(12)
- Francis D, Hodgkinson J, Livingstone B & Tatam RP. (2015). Quantum cascade laser light propagation through hollow silica waveguides. Applied Physics B, 119(1)
- Hodgkinson J & Tatam RP. (2013). Optical gas sensing: a review. Measurement Science and Technology, 24(1)
- Hodgkinson J, Smith R, Ho WO, Saffell JR & Tatam RP. (2013). Non-dispersive infra-red (NDIR) measurement of carbon dioxide at 4.2μm in a compact and optically efficient sensor. Sensors and Actuators B: Chemical, 186
- Hodgkinson J, Masiyano D & Tatam RP. (2013). Using integrating spheres with wavelength modulation spectroscopy: effect of pathlength distribution on 2nd harmonic signals. Applied Physics B, 110(2)
- Hodgkinson J & Pride RD. (2010). Methane-specific gas detectors: the effect of natural gas composition. Measurement Science and Technology, 21(10)
- Masiyano D, Hodgkinson J & Tatam RP. (2010). Gas cells for tunable diode laser absorption spectroscopy employing optical diffusers. Part 2: Integrating spheres. Applied Physics B, 100(2)
- Hodgkinson J, Masiyano D & Tatam RP. (2010). Gas cells for tunable diode laser absorption spectroscopy employing optical diffusers. Part 1: single and dual pass cells. Applied Physics B, 100(2)
- Hodgkinson J, Masiyano D & Tatam RP. (2009). Using integrating spheres as absorption cells: path-length distribution and application of Beer's law. Applied Optics, 48(30)
- Masiyano D, Hodgkinson J, Schilt S & Tatam RP. (2009). Self-mixing interference effects in tunable diode laser absorption spectroscopy. Applied Physics B, 96(4)
- HODGKINSON, J. (2009). Gas sensors 2. The markets and challenges. Nanotechnology Perceptions, 5(1)
- HODGKINSON, J. (2009). Gas sensors 1. The basic technologies and applications. Nanotechnology Perceptions, 5(1)
- Masiyano D, Hodgkinson J & Tatam RP. (2008). Use of diffuse reflections in tunable diode laser absorption spectroscopy: implications of laser speckle for gas absorption measurements. Applied Physics B, 90(2)
- Masiyano D, Hodgkinson J & Tatam RP. (2007). Methodology for investigation of diffuse reflections in tunable diode laser absorption spectroscopy. Journal of Physics: Conference Series, 76(1)
- Hodgkinson J, Shan Q & Pride RD. (2006). Detection of a simulated gas leak in a wind tunnel. Measurement Science and Technology, 17(6)
- Gibson G, Well BV, Hodgkinson J, Pride R, Strzoda R, .... (2006). Imaging of methane gas using a scanning, open-path laser system. New Journal of Physics, 8(2)
- Hodgkinson J, Johnson M & Dakin JP. (2005). Performance of a photothermal detector with turbid liquids. Applied Optics, 44(20)
- Hodgkinson J, Johnson M & Dakin JP. (2005). Quantitative analysis of a closed photoacoustic cell that uses a high compliance piezoelectric transducer. Journal of Applied Physics, 98(8)
- Well BV, Murray S, Hodgkinson J, Pride R, Strzoda R, .... (2005). An open-path, hand-held laser system for the detection of methane gas. Journal of Optics A: Pure and Applied Optics, 7(6)
- Hodgkinson J, Johnson M & Dakin JP. (2000). Comparison of self-referencing techniques for photothermal detection of trace compounds in water. Sensors and Actuators B: Chemical, 67(3)
- Hodgkinson J, Johnson M & Dakin JP. (1998). Photothermal detection of trace optical absorption in water by use of visible-light-emitting diodes. Applied Optics, 37(31)
- Hodgkinson J, Johnson M & Dakin JP. (1998). Photothermal detection of trace compounds in water, using the deflection of a water meniscus. Measurement Science and Technology, 9(8)