Oct 26

Photonex 2017

In October, the Engineering Photonics team attended Photonex 2017; the UK’s premier showcase event for photonics and light-based technologies. The event was held at the Ricoh Arena in Coventry; home of the Wasps rugby team and Coventry City football club.

We were one of more than 90 companies and institutions exhibiting and were there to demonstrate some of the optical sensing and measurement solutions that we have been developing. The systems on display were the same as those presented at the trade show in Munich earlier in the year with the addition of a dual-channel swept source optical coherence tomography system for measurement of flow velocity in micro-fluidic channels.

The Engineering Photonics stand at Photonex '17

More details on the individual demonstrators can be found here.

In addition to the trade show, the event hosted The Enlighten Conference, which included over 120 speakers in 15 programmes. Engineering Photonics had three talks in the conference, all within the Optical Metrology for Manufacturing programme.

‘Position measurements for manufacturing applications using range-resolved interferometry’
T. Kissinger

‘Dual-plane optical coherence tomography imaging for velocity measurement in small-scale flows’
E. Rigas, J. M. Hallam, H. D. Ford, T. O. H. Charrett, and R. P. Tatam

Laser speckle correlation sensing for industrial robots’
T. O. H. Charrett

Jul 17

Laser: World of Photonics, Munich 2017

In June, 8 members of the Engineering Photonics team attended the Laser World of Photonics trade show in Munich. This is one of the world’s largest trade shows for optics and photonics and is held biennially at Messe München to the east of the city. This year there were nearly 1,300 exhibitors and more than 32,000 visitors.

 

The Neues Rathaus on Marienplatz.

We were there to exhibit a series of demonstrated experiments from a range of research areas within the group, including wavelength control, optical gas sensing, fibre-based interferometric sensing, and laser speckle odometry. More details on the individual demonstrators can be found here

 

The completed stand.

After a hot and tiring first few days setting up the stand and all the demonstrators, we were finally ready to begin the show. Although we were dwarfed by the Hamamatsu stand opposite, ours looked very impressive and professional by the time it was completed. The stand was very popular and we had many visitors, both new and well-known, from companies and universities around the world. It was a job to keep track of all the business cards that we had acquired!

 

At one of the quieter times during the fair.

In addition, the trade fair is held in conjunction with the World of Photonics Congress which holds a number of conferences including SPIE Optical Metrology, and CLEO. The group had three talks in the conferences presented by Thomas, Vangelis, and Tom. Details of the talks are provided below.

It was a very busy week but we still found plenty of time to enjoy the sights of Munich and the Bavarian beer and sausage!

 

Jane, Ralph, Kevin, Vangelis, Tom, Thomas, and Steve (L-R) enjoying a drink at the Ratskeller.

Conference presentations

Laser speckle velocimetry for robot manufacturing
T O H Charrett, Y K Bandari*, F Michel*, J Ding*, S W Williams*, and R P Tatam
Presented at Optical Measurement Systems for Industrial Inspection X (Part of SPIE Optical Metrology), Munich, Germany, June 2017
Proc. SPIE 10329 Article number 103291Z (2017)
*Welding engineering and laser processing centre, Cranfield University, UK

Interferometric fibre-optic curvature sensing for structural, directional vibration measurements
T Kissinger, E Chehura, S W James, and R P Tatam
Presented at Optical Measurement Systems for Industrial Inspection X (Part of SPIE Optical Metrology), Munich, Germany, June 2017
Proc. SPIE 10329 Article number 1032925 (2017)

Microfluidic velocity measurement using dual-plane optical coherence tomography imaging
E Rigas, J M Hallam, T O H Charrett, H D Ford, and R P Tatam
Presented at the Conference on Lasers and Electro-Optics, Munich, Germany, June 2017

Feb 28

Photonics West, San Francisco 2017

 

San Francisco skyline from Yerba Buena island. (photo © D.Francis)

 

Photonics West, the world's largest multidisciplinary event for optics and photonics with over 20,000 delegates, was held at the Moscone Centre in San Francisco from 28th January to 2nd February 2017. Engineering Photonics was represented by Daniel Francis and Sergiy Korposh (now a lecturer at Nottingham University) who presented their work at the BIOS conference which specialises in biophotonics, biomedical optics and imaging.

 

Sergiy and Dan at the Bios conference, Photonics West.

 

Dan presented work on spectroscopy for point-of-care diagnostics using mid-infrared quantum cascade lasers and Sergiy presented a paper on biomedical application for optical fibre sensors.

 

 

Sep 23

Engineering photonics at FLAIR 2016

The FLAIR conference, now in its 5th edition, brings together industrial and academic researchers to explore and discuss field laser applications for sensitive and selective detection of molecular species. This edition was held for the first time in the beautiful French mountain resort town of Aix-les-Bains. With a particular interest in gas sensing applications, Jane, Sarah and Nick attended, presenting three posters describing their work on both the use of integrating spheres as gas cell and the use of specific lasers for methane detection.

Sarah, Jane, and Nick attending the FLAIR conference in Aix-les-Bains.

Sarah, Jane, and Nick visiting the Château de Menthon-Saint-Bernard near Annecy during the FLAIR conference.

 

The poster topics are as follows:

 

Methane detection using an external cavity Bragg grating stabilised laser at 1651nm

N.M. Davis, S.G. Lynch, J.C. Gates, J. Hodgkinson, P.G.R. Smith and R.P. Tatam

Typically, commercially available laser diodes in the near infrared have to be custom made at a particular wavelength, such as Distributed Feedback (DFB) lasers. This requires significant investment with potentially low yields. The latest results in the development of a new, external cavity, Bragg stabilised laser for tunable diode laser spectroscopy (TDLS) were presented. The design uses a silicon-on-silicon platform incorporating a UV written Bragg grating as the wavelength selective element of the laser cavity. Thus, custom wavelengths can be written “on demand” with relatively low capital investment.

 

High frequency modulation for pathlength calibration of an integrating sphere

S. Bergin, T. Kissinger, J. Hodgkinson, and R.P. Tatam

Pathlength calibration presents one of the major challenges for integrating sphere gas cells as the achievable pathlength is a sensitive function of the sphere wall reflectivity. The use of high frequency laser intensity modulation allows for the pathlength to be calculated in real time, and without the requirement for a reference gas cell.

Setup used for high frequency laser intensity modulation for integrating sphere pathlength calibration.

Setup used for high frequency laser intensity modulation for integrating sphere pathlength calibration.

ICL based TDLS instrument developed for airborne measurements of atmospheric methane.

ICL based TDLS instrument developed for airborne measurements of atmospheric methane.

Detection of methane at 3.3µm using an integrating sphere and Interband Cascade Laser for environmental applications

N.M. Davis, D. Francis, J. Hodgkinson and R.P. Tatam

Several platforms are used worldwide for airborne atmospheric monitoring of various gases, based on tunable diode laser spectroscopy (TDLS). For high signal-to-noise ratios multipass optical cells are used, which are difficult to align and increase the problem of optical interference fringes. On aircraft, high levels of vibration and large temperature fluctuations compromise performance compared with laboratory operation. We have developed a gas sensor for use on aircraft using an ICL, allowing for the detection of the fundamental absorption bands of methane at 3.3µm, and an integrating sphere as the gas cell. These cells are easy to align, insensitive to vibration and do not produce interference fringes.

Jul 27

Fully funded PhD studentships in Engineering Photonics!

EP_studentships

We are currently looking for five PhD students to join us, working on a range of projects including;

To make enquires or submit an application, please contact Prof. Ralph Tatam, Head of Engineering Photonics [email protected]

The full advertisement can be downloaded here

Jul 25

Lord Kings Norton Medal goes to Engineering Photonics student

Former Engineering Photonics PhD student Thomas Kissinger, who now works as a research fellow within the group, has won Cranfield Universities’ highest honour for doctoral students, the Lord Kings Norton Medal for his PhD thesis1 entitled “Range-resolved optical interferometric signal processing”.

Graduation Day

Graduation Day

The medal was presented as part of this years’ graduation ceremony on the 8th of July 2016. This medal is awarded annually to the most outstanding doctoral student of the year and is the only prize for which students compete across the two campuses of the University.  The award was established in 1978 by our former Chancellor, Lord Kings Norton of Wotton Underwood, who sadly passed away in 1997, aged 95 years.

LordKingsNorton

Front and back of Lord Kings Norton medal

References:

1. T. Kissinger,  "Range-resolved optical interferometric signal processing”, PhD Thesis, Cranfield University (2015).

 

Jul 05

International Conference on Vibration Measurements by Laser Techniques and Non-Contact Techniques

Results from the multi-surface vibrometry system developed at by Engineering Photonics1,2 at Cranfield University were presented by Thomas Kissinger at the 12th International conference on laser vibration measurements held in Ancona, Italy.

Figure 1 The conference was held in the historic Muse theatre in the heart of Ancona.

Figure 1 The conference was held in the historic Muse theatre in the heart of Ancona.

Apart from the obvious benefits of good food, nice weather and historic surroundings, see Fig. 1, the long running Ancona laser vibrometry conference is the premier conference in the field. It is a suitable venue to present our work on multi-surface vibrometry, which allows displacement signals from multiple semi-reflecting surfaces along a single laser beam to be evaluated simultaneously. This new technique allowed the concurrent measurement of differential and common-mode vibrations of the cryostat (see Fig. 2) and could also be of use in other situations where differential displacement or vibration measurements are required.

Multi_Surface_Vibrometry_Small

Figure 2 Typical measurement results obtained from an optical cryostat, showing how differential measurements (bottom) can be extracted from the two directly measured signals of the cryostat window and target (top).

References:

Apr 18

Engineering Photonics participation in the 2016 Set for Britain poster competition

Thomas Kissinger and Matthew Partridge from the Engineering Photonics group travelled to the Westminster Parliament on the 7th of March 2016 to present their science to an audience of parliamentarians and representatives of learned societies as part of the Set for Britain competition for early stage researchers organised by the UK Parliamentary and Scientific Committee.

The poster presentation was held at Portcullis House, which is part of the UK Westminster Parliament Complex in London.

The poster presentation was held at Portcullis House, which is part of the UK Westminster Parliament Complex in London.

Matthew took part in the Chemistry competition with a poster entitled “Fibre Optic Chemical Sensing”, while Thomas took part in the Engineering competition with a poster named “A Fresh Look at Optical Interferometry”. They were among the 60 presenters competing for each category. Although neither of them won a prize, it was interesting experience and a chance to update the Engineering Photonics poster collections with a new set of posters aimed at a general, non-scientific audience. In the true spirit of open science these posters are publicly available via our new Cranfield University Figshare account1,2.

Matthew posted a description of his experience at the conference on his blog, Errant Science.

 

References:

“A Fresh Look at Optical Interferometry” by Thomas Kissinger

“A Fresh Look at Optical Interferometry” by Thomas Kissinger

“Fibre Optic Chemical Sensing“ by Matthew Partridge

“Fibre Optic Chemical Sensing“
by Matthew Partridge

Mar 17

Featured in Lights

Dr Divya Tiwari of Engineering Photonics has been included in as a case study in 'Lights', a resource developed by Royal Academy of Engineering in the area of optics. The resource has several optics based experimental activities, including the investigation of polarization, refraction, and dispersion, and is aimed at Key Stage 3 (age 11-14) pupils and fits into the national curriculum.

Divya

Divya's feature in the RAE's 'Lights' brochure

 

Jan 05

Publication update: imaging interferometry

ImagingInterferometry

A recent paper, published in the IOP journal Measurement science and technology describes the application of infinity corrected lenses, commonly used for microscope objectives, for full-field interferometry applications such as optical flow measurement and speckle interferometry. The paper “Full-field interferometry using infinity corrected optics” describes critical considerations for constructing path-length imbalanced full-field interferometers using such lenses, including the concept of balancing the infinity-spaces of the two arms of the interferometer via the use of a glass block, convenient methods for phase shifting, and the introduction of carrier fringes in the interferograms.

The full-paper is available now from Measurement science and technology:
Full-field interferometry using infinity corrected optics
T O H Charrett and R P Tatam
Measurement Science and Technology, Volume 27, Number 1, 015402 (8pp) (http://iopscience.iop.org/0957-0233/27/1/015402)

Or via CERES https://dspace.lib.cranfield.ac.uk/ (Cranfield University institutional repository).