Advancing Clean Energy Research and Biosecurity through Novel Bragg Grating Technologies
Submitting InstitutionUniversity of Southampton
Unit of AssessmentElectrical and Electronic Engineering, Metallurgy and Materials
Summary Impact TypeTechnological
Research Subject Area(s)
Physical Sciences: Other Physical Sciences
Engineering: Materials Engineering
Technology: Communications Technologies
Summary of the impact
Ultra-precise Bragg grating writing-technology, invented in the
Optoelectronics Research Centre (ORC), has led to impacts in the areas of
security, safety, detection of bio-hazards and the underpinning
laser technology currently being pursued for clean energy
generation for future energy security. This case study highlights two
aspects of the technology namely: planar-based for optical
microchip sensors in areas such as portable detection of biohazards, which
has resulted in the spin-out Stratophase, and fibre-based,
inside the US National Ignition Facility (NIF), the world's largest laser
system, based in California, built for fusion-energy research, which has
ORC fabricated fibre Bragg gratings within its laser amplifier chains.
These ultra-high precision laser-written engineered gratings have enabled
important advances in biosecurity, management of environmental hazards and
clean energy research.
The underpinning research uses a process of UV (244nm) stroboscopic laser
direct-writing which has been applied in both geometries. For fibre-based
gratings (FBG), the underpinning research has been focussed
on ORC specialty fibres with combined functionality of high rare-earth
concentrations and high levels of photosensitivity, and
inscription/fabrication-techniques capable of producing gratings of very
long length (>1metre) with unprecedented phase- and amplitude-
complexity. For planar-based gratings (PBG) the challenge is
to obtain highly uniform waveguides and gratings. A technique was
developed to write the gratings and waveguide simultaneously. This
approach allows the creation of sensors in a fluidic compatible format
that allows for sensing of multiple chemical or biochemical targets.
Fibre Bragg Grating underpinning research has focussed on
- Development of high-concentration rare-earth doped (e.g. Yb3+,
Er3+, or a combination of both) photosensitive fibres
suitable for direct writing of short-cavity, high-efficiency,
single-frequency fibre-lasers with output powers in the 10's of mW
range, including research on glass spectroscopy and design of
application-specific grating spatial and phase profiles.
- Demonstration and characterisation of high-performance rare-earth
doped distributed feedback fibre-lasers yielding ultra-low phase- and
intensity-noise. This work led to the first demonstration of all-fibre
lasers operating in the important 1.5µm telecommunications wavelength
band [3.1 and US Patent 5,771,251], and soon after to the
demonstration of fibre- lasers in Yb3+ co-doped fibres
operating in the 1µm wavelength region, as required for the front end of
the NIF laser-system [3.2]. These distributed feedback fibre-lasers, all
of which are based on our original technology, are now sold by several
companies (NKT Photonics, Redfern Optical Components, IDIL Fibres
- Design of FBG fabrication methods to achieve full control of the
phase- and amplitude-profile of grating-devices to allow for very
complex apodisation and phase-shifted all-fibre structures [3.3 and US
Patent Nos. 6,072,926 & 6,334,013 & 6,384,977].
Planar Bragg Grating underpinning research has focussed on
- New ways of creating optical waveguides with integrated gratings, by
developing a single-step writing-process that optimises both of these
- A technology that has been used to develop sensors by exposing the
gratings to a fluid through an etched window. If the refractive index of
the medium (for example water or antibodies) at the waveguide surface
changes, this can then be sensed with extremely high precision by
monitoring the wavelength that is back-reflected [3.5].
- Several gratings can be integrated along one waveguide so that
multiplexed measurements at each grating site may be made, and if each
grating is made sensitive to a different biochemical analyte, then
multiple analytes may be detected simultaneously with extreme
- All the research on Bragg grating technology was carried out under
several large-scale EPSRC research-grants [G1, G2, G4, G5, G6] while the
underpinning research on the grating inscription was funded via
industrial-funding from Pirelli Cavi SpA [G3].
This research was carried out between 1994-2008 (FBG), and
1998-2013 (PBG) respectively, involving the following Sir David N.
Payne, (Director ORC). Jon T. Kringlebotn, (Visiting
researcher from Optoplan A/S 1994-1996). Wei H. Loh, (Senior
Research Fellow, joined Bragg Photonics Inc., Canada in 1997, returning to
the ORC in 2004). Richard I. Laming, (Deputy Director ORC. Left
the ORC to form spin-out Kymata Ltd. in 1998). Michalis N. Zervas,
(Senior Research fellow, now Chief Scientist of ORC spin-out SPI lasers).
Martin J. Cole (Ph.D.-student, joined QTERA, USA, in 1999). Morten
Ibsen (Ph.D.-student, now Reader in the ORC). Michael K. Durkin
(Ph.D.-student, joined SPI lasers in 2000). Peter G.R. Smith
(Professor, ORC and co-founder of Stratophase in 2003). Richard B.
Williams (Senior Research Fellow in the ORC, became CEO of
Stratophase in 2003). Sam P. Watts (Ph.D.-student in the ORC,
became Business Development Officer of Stratophase in 2003). Greg. D.
Emmerson (Ph.D.-student in the ORC, became CTO of Stratophase in
2003). Corin B.E. Gawith (Principal Research Fellow, seconded to
Covesion/Stratophase in 2009).
References to the research
(best 3 are starred)
*[3.1] J.T. Kringlebotn, J.-L. Archambault, L. Reekie, D.N. Payne,
`Er3+:Yb3+ -codoped fiberdistributed-feedback
laser', Optics Letters, 19, p.2101, 1994.
[3.2] D.F. Browning, G.V. Erbert, `DFB Fiber Laser: The Heart of the
National Ignition Facility' Lawrence Livermore National Laboratories, NIF
report, UCRL-ID-155446, 2003.
*[3.3] M. Ibsen, M.K. Durkin, M.J Cole, R.I. Laming, `Sinc-sampled
fiber Bragg gratings for identical multiple wavelength operation' Photon.
Technol. Lett., 10, p. 842, 1998.
*[3.4] G.D. Emmerson, S.P. Watts, C.B.E. Gawith, V. Albanis, M.
Ibsen, R.B. Williams, and P.G.R. Smith, "Fabrication of directly
UV-written channel waveguides with simultaneously defined integral Bragg
gratings," Electronics Letters, 38, p. 1531, 2002.
[3.5] G.D. Emmerson, C.B.E. Gawith, I.J.G. Sparrow, R.B. Williams, and
P.G.R. Smith, "Physical observation of single step UV-written integrated
planar Bragg structures and their application as a refractive-index
sensor," Applied Optics, 44, p. 5042, 2004.
[3.6] R. M. Parker, J.C. Gates, M.C. Grossel, and P.G.R. Smith, "In vacuo
measurement of the sensitivity limit of planar Bragg grating sensors for
monolayer detection," Applied Physics Letters, 95, p.
[G1] IRC in optical and laser related science & technology, EPSRC
grant GR/J62036/01, W.A. Gambling, 1/4/1994 to 1/10/1996, £6,952,536
[G2] IRC rolling grant: The Optoelectronics Research Centre, EPSRC grant
GR/L26971/01, D.N. Payne & D.C. Hanna, 1/10/1996 TO 30/09/2000,
[G3] Rolling Pirelli Cavi SpA contracts, D.N. Payne, 1997 - 2000,
[G4] Advanced optical fibre and waveguide devices and microstructured
optical materials, EPSRC grant GR/M81854/01, P.I = D.N. Payne, 1/10/1999 -
[G5] Fabrication of Microstructured Glass & Crystal Photonic
Materials & Devices , EPSRC grant GR/T11746/01, P.I. = D.N. Payne
1/4/2004. Subsumed into Portfolio Partnership in Photonics, 30/9/2004,
[G6] Portfolio Partnership in Photonics, EPSRC grant EP/C515668/1, P.I
was. D.N. Payne, 1/10/2004 - 31/3/2011, £7,179,095.
Details of the impact
The impact for our Bragg grating technology spans several related areas,
which reflect the intrinsic characteristics of fibre (FBG) and planar
(PBG) geometries. Impact here relate to Economic (spin-out,
creation of new business and adoption of new processes) as well as Environmental
(achievement of environmental (green) objectives).
FBG research has been directed at a wide range of technologies,
but the focus here is for NIF, the National Ignition Facility, in
Livermore, California, U.S.A. This is a massive enterprise aimed at fusion
research, (which is hoped will replace current fission-based power
stations) and which has at its heart, ORC-developed passive and active
fibre Bragg grating technology.
The FBG process that led from research to impact was via the ORC
involvement from an early stage of the developments of NIF, and concerned
the contributed key technology and knowhow that was developed through FBG
and optical amplifier designs. The 192 laser beams in NIF originate from a
single 5cm long DFB fibre-grating-laser master-oscillator conceived as a
concept and first demonstrated at the ORC. The critical
requirement is that this laser operates at the precise wavelength required
for all downstream laser and amplifier components [5.1, 5.2], and was
chosen because of its exceptional wavelength and power-stability. Precise
pulse control in the preamplifiers and the signal delivery fibres within
NIF is done with 30cm long ORC-fabricated passive chirped FBGs. The
critical operational requirements (long length, exact matching of passive
dispersion-orders and low phase-noise) can only be achieved with
ORC-fabricated gratings as there are no commercial suppliers or any other
research organisations that are capable of delivering these requirements.
It was this unique capability that led to NIF scientists
collaborating directly with the ORC [5.3].
The nature of the impact is the possibility that fusion-based
energy generation can provide that unlimited source of clean energy that
would solve one of our most fundamental problems. Fusion has been termed
the 'holy grail' and `game-changer' of future energy technology, and it
has vast potential to help meet the world's future energy challenges. The
success and promising concepts demonstrated at NIF are already spilling
over into beneficiaries in Europe, China and Russia where several
facilities are under construction creating new jobs in the industry, and
promoting high-tech laser-development [5.4]. While it is recognised that
there are many challenges remaining to be solved, it is undeniable that
cheap and renewable energy is perhaps number one on the wish-list of every
government. The world is closely following the fusion energy programme,
which, should it prove successful, would solve one of the most fundamental
problems of energy security. It is a testament to its
significance that grating-technology researched and developed at the ORC
lies at the very heart of the quest for controlled fusion, and that a
significant step towards this goal was reached on 5-July 2012 by NIF
reaching its 1.8MJ, 500TW milestone [5.5], and on 13-August 2013 when, for
the first time ever from any fusion facility in the world, the amount of
energy released through the fusion reaction exceeded the amount of energy
being absorbed by the fusion fuel [5.6].
The PBG process started from 1999, when Bragg gratings in planar
geometries were developed, together with the first proof of concept for
sensors. Prompted by feedback from industry, the University of Southampton
patented the inventions (e.g. US Patent No. 7,440,653, filed May-2003,
issued October-2008) and attracted VC-funding to establish the spin-out
Stratophase, which initially had two core technologies, UV-written Bragg
gratings and periodically poled lithium niobate (PPLN). The second of
these was itself spun out in 2009 in another company, Covesion, which is
the subject of a different case study. Soon after the first VC-funding,
two patents were filed on evanescent field sensors utilising the original
grating patent (US Patent No. 7,715,005, filed July-2005, issued May-2010,
US Patent No. 7,541,573, filed July-2005, issued June-2009).
The nature of the impact and beneficiaries: Stratophase has led to
high-tech employment (presently 12 staff), investment by US
Investors of £6.8m, and cumulative sales and development contracts worth
£3.2m [5.7]. Users of this technology include:
- CPI, Glaxo-Smith-Kline, Greenbiologics, for feedback control during
- DSTL and the MoD who successfully demonstrated detection of live agent
bio-hazards at Porton Down including ricin and anthrax, providing the UK
with a national capability for detection of these bio-hazards
- A number of life sciences companies [5.9] via the launch of a new set
of products (Stratophase Ranger™) offering off-the-shelf solutions for
batch monitoring and process-control.
- The University of Cambridge's Institute of Biotechnology, Bristol
Industrial and Research Associates and the Chelsea Technologies Group.
In June 2011 Stratophase reported the successful completion of a
feasibility study into a portable sensor unit for detecting foot-and-mouth
disease, which could allow veterinarians, inspectors and
even farmers to diagnose the disease much more quickly than is currently
possible using laboratory analysis [5.9].
- A contract with Biral, for the development and demonstration of live
agent air-sampled detection capability at the Porton Down BSL 4
lab for the most toxic materials (e.g. Anthrax). The contract, awarded
by the MOD/DSTL, was for £1.2m and is an excellent example of University
research having impact on the work of Government scientists for greater
protection of the UK population. [5.10]
Sources to corroborate the impact
Corroboration of DFB fibre lasers and chirped Bragg grating use in
NIF, impact of NIF technology and milestones:
[5.1] `Special Issue: Laser Technology for the National Ignition
Facility', ICF Quarterly Report: October-December 1998, vol.9 no.1:
[5.2] D.F. Browning, G.V. Erbert, `DFB Fiber Laser: The Heart of the
National Ignition Facility', Lawrence Livermore National Laboratories, NIF
report, UCRL-ID-155446, 2003.
[5.3] Barty, C.P.J. et al., `An overview of LLNL high-energy short-pulse
technology for advanced radiography of laser fusion experiments', Nucl.
Fusion, vol. 44, no. 12, S266, 2004. Contact: Chief Technology Officer for
NIF and Photon Science.
and and Savage, L.: `HiPER to expand Europe's role in laser-driven nuclear
fusion technology', Photonics.com, June 2012.
Contact: Director for Laser Fusion Energy at LLNL.
[5.5] Editorial: `Laser fusion on the horizon', Nature Photonics, vol. 6,
p. 267, 2012. and Hatcher, M.: `NIF `tantalizingly close' to ignition
Corroboration of the formation and operation of Stratophase, and
impact of PBG sensors:
and Watts S., Bragg gratings: Optical microchip sensors, Industry
Perspective: `Bragg gratings: Optical microchip sensors, Industry
Perspective', Nature Photonics, vol. 4, p. 433, 2010. doi:10.1038/nphoton
[5.9] Contact: CEO of Stratophase