Professor Brian Culshaw

Publications

Multi-component gas measurement aliasing spectral demodulation method for interference separation in laser absorption spectroscopy

Wang Qianjin, Sun Pengshuai, Zhang Zhirong, Zhang Lewen, Pang Tao, Wu Bian, Xia Hua, Guo Qiang, Sigrist Markus W, Culshaw Brian

Sensors and Actuators B: Chemical Vol 369 (2022)

https://doi.org/10.1016/j.snb.2022.132292

Laser ultrasound measurement of diaphragm thickness, Young's modulus and Poisson's ratio in an MEMS device

Mckee Campbell, Culshaw Brian, Leach Richard

IEEE Journal of Selected Topics in Quantum Electronics Vol 23 (2017)

https://doi.org/10.1109/JSTQE.2016.2635518

Fibre optics in sensing and measurement - achievements and opportunities

Culshaw Brian

2015 2nd International Conference on Opto-Electronics and Applied Optics 2nd International Conference on Opto-Electronics and Applied Optics, IEM OPTRONIX 2015 (2015)

https://doi.org/10.1109/OPTRONIX.2015.7345509

Temperature calibration of optical fiber attenuation differences induced measurement error of raman distributed temperature sensor

Tang Yuquan, Sun Miao, Li Jun, Yang Shuang, Culshaw Brian, Dong Fengzhong

Proceedings of SPIE - The International Society for Optical Engineering 24th International Conference on Optical Fibre Sensors (2015)

https://doi.org/10.1117/12.2194687

Study on the effect of temperature additional fiber loss on measurement error of Raman distributed optical fiber temperature sensor

Tang Yu Quan, Sun Miao, Yang Shuang, Culshaw Brian, Dong Feng Zhong

Guangdianzi Jiguang/Journal of Optoelectronics Laser Vol 26, pp. 847-851 (2015)

Wavefront integrating fiber sensors for ultrasonic detection

Sorazu B, Thursby G, Culshaw B

IEEE Sensors Journal Vol 11, pp. 1623-1631 (2012)

https://doi.org/10.1109/JSEN.2010.2097247

More publications

Research Interests

Fibre optic sensor systems for physical and chemical parameter measurement, structural instrumentation for on-line testing of mechanical systems including signal generation and acquisition and data interpretation.

Projects

Ultrasonic Measurement and Beamforming using Optical Sensors

Pierce, Gareth (Principal Investigator) Culshaw, Brian (Co-investigator) Hayward, Gordon (Co-investigator) Stewart, George (Co-investigator) Thursby, Graham (Co-investigator)

The proposal describes the fundamental development and response quantification of sensitive, lightweight optical sensors for ultrasonic monitoring applications. The principal research components centre on providing a comprehensive theoretical and experimental understanding of the basic interactions between ultrasonic strain fields and optical fibre bragg grating (FBG) sensors. Two potential exploitation examples of the technology provide the background and application context for this research: ultrasonic beamforming in sonar arrays, and acoustic emission detection in structural health monitoring. These areas were carefully selected as they encompass the typical amplitude range of ultrasonic signals commonly encountered in engineering applications (in transmit sonar arrays the displacement fields are of high amplitude, often many 10's of nanometres, whereas in acoustic emission applications, the displacement field amplitudes may be lower than 100 picometres). Letters of support from THALES Underwater Systems (Sonar systems) and AIRBUS UK (Structural Health Monitoring) are included to help demonstrate the value of this work. Of course the opportunities for ultrasonic array monitoring are not confined to sonar systems. The increasing use of complex coded sequence actuation for ultrasonic arrays demonstrates a growing demand for improved ranging accuracy and resolution in sonar, non destructive testing and medical ultrasound fields. The potential for a lightweight, non-intrusive ultrasound field monitoring capability in such arrays provides a unique capability to provide absolute (calibrated against optical wavelength) measurement of the amplitude and phase characteristics at the output of these arrays. Such measurements facilitate calibration, optimisation of beamforming algorithms, and the capability to continuously monitor real-time changes under operational conditions. If successful the research will enable a step change for both areas of application in addition to related fields.

01-Jan-2008 - 31-Jan-2011

Micromaterials and microstructures - non contact characterisation using optical techniques

Culshaw, Brian (Principal Investigator) Johnstone, Walter (Co-investigator) Pierce, Gareth (Co-investigator) Stewart, George (Co-investigator) Thursby, Graham (Co-investigator) Uttamchandani, Deepak (Co-investigator)

Microscale Structures are becoming increasingly important in applications ranging from biological implants to display technologies. An essential characteristic of microstructures is their mechanical properties. Performing repeatable and accurate measurements of these properties on operational structures has to date proved to be extremely difficult. Such monitoring would enable the effects of fabrication steps during manufacture on mechanical properties to be reliably characterised. Additionally it would enable ready assessment of the impact of packaging, environmental conditions and continuous usage on mechanical integrity. This project focuses upon monitoring these mechanical properties (density, stiffness etc.) using a non contact optical technique. This approach uses an optical signal to produce an ultrasonic response in the material and this response is monitored optically. The complexity of this response enables the determination of mechanical material properties through curve fitting involving carefully structured numerical mathematical inversion techniques. For simple structures the response can be modelled analytically and this analytical model inverted numerically. For more complex structures reliable computer modelling is essential for both forward and inverse analysis. The project therefore has parallel strands examining both simple and more complex microstructures and making extensive use of finite element modelling techniques where appropriate to augment the experimental techniques. Additionally for very simple structures the measurement method will be referenced against contact based systems developed through our partners at the National Physical Laboratory. We have demonstrated the basic principle on larger scale geometrically simple structures and are confident that repeatability in the order of 1% is achievable. Extending the technique to microstructures does however present significant research challenges in realising gigahertz bandwidth ultrasonic excitation (where the wavelength is comparable to structural dimension) and detection and in accommodating more complex structural artefacts, in addition to producing microscale detection and excitation optics.

01-Jan-2007 - 28-Jan-2011

Doctoral Training Grant 2006 / RA4033

Culshaw, Brian (Principal Investigator)

01-Jan-2006 - 30-Jan-2010

OPTICAL FIBRE SENSORS FOR HIGH SENSITIVITY GAS DETECTION

Culshaw, Brian (Principal Investigator) Johnstone, Walter (Co-investigator)

Near infra-red (IR) tuneable diode laser spectroscopy (TDLS) has become a powerful technique in many areas of gas sensing. In particular, interest in TDLS over optical fibre is growing for remote (sometimes multi-point) applications in difficult or hazardous environments / locations. The overall aim of this project is to enhance the sensitivity of TDLS over optical fibre by three to four orders of magnitude to enable its application to the detection of trace gases such as toxins, nerve gases or other species that may represent a security threat and vapour by products of the decomposition of explosives or other hazardous chemicals. A dual approach will be adopted. The first is a relatively low risk approach to gaining two to three orders of magnitude enhancements in the near IR system through careful optical design and enhanced optical and electronic signal processing to eliminate etalon fringes and improve the signal to noise ratios. In the second, more radical, approach we will investigate the use of guided wave, non-linear CW parametric difference frequency generation (DFG) devices at the remote gas cell to generate mid IR idler wavelengths from near IR pump and signal waves transmitted over optical fibre. This will enable, for the first time, the much stronger (by 2 / 3 orders of magnitude) mid IR fundamental absorption lines to be addressed using TDLS over optical fibre. A variation of the basic DFG technique / the singly resonant optical parametric oscillator - will enjoy all the benefits of signal modulation (TDLS techniques), optical fibre transmission, recovery and detection in the near IR, whilst exploiting the sensitivity gains associated with the much stronger fundamental absorption lines of the mid IR. Sensitivities well below the part per billion level are anticipated.

01-Jan-2006 - 30-Jan-2009

NEMO

Culshaw, Brian (Principal Investigator) Uttamchandani, Deepak (Co-investigator)

01-Jan-2004 - 31-Jan-2008

Collaborative Training Account / RA4046

Culshaw, Brian (Principal Investigator)

01-Jan-2004 - 30-Jan-2012

More projects