Engineered nonlinear materials for the optoelectronics market
Submitting InstitutionUniversity of Southampton
Unit of AssessmentPhysics
Summary Impact TypeTechnological
Research Subject Area(s)
Physical Sciences: Optical Physics, Other Physical Sciences
Summary of the impact
Covesion, a company that was spun out of the University of Southampton,
focuses on research and development of high-value engineered nonlinear
crystal materials, that find widespread use in the laser, defence and
display sectors. The impacts of their work fall under the headings of economic,
via job creation and investment, health, through
application of their products in medical imaging, and the environment,
via detection of airborne pollutants and remote sensing. The company is
now a multi-million pound business that has attracted more than £1m in US
investment and won UK export orders around the world. The global value of
Covesion-enabled commerce since the company's inception in 2009 is
estimated to be in excess of US$100m.
Nonlinear optical materials are used to manipulate some of the
fundamental properties of light (almost invariably laser light) in terms
of its wavelength, bandwidth or spectral content, by the judicious choice
or manipulation of their nonlinear optical coefficients. The field of
nonlinear optical research has grown rapidly following the invention of
the laser in 1960. Although it may be comparatively easy to demonstrate
laser action in a particular material, unless the lasing wavelength
produced is optimum for the end application, nonlinear optical techniques
are needed to convert the primary wavelength into the one required, and to
do this with the highest efficiency possible.
One technique for achieving such efficient wavelength conversion is
called `quasi-phase-matching', which involves the manipulation of a
crystal structure by periodically modifying its internal crystalline
properties (specifically modifying the sign of specific nonlinear
coefficients) at length scales that fall into the few micron range.
Suggested first in the early 1960s, little practical progress was made in
the area until the early 1990s, when techniques emerged to successfully
fabricate these engineered crystals with the correct periodicity and
quality. Three research groups at Sony corporation in Japan, Stanford
University in California, and the laser group at Southampton (see below
for details), independently developed and refined the fabrication
techniques required, using lithium niobate crystals as the optimum
starting material, to produce the final product known as PPLN
(periodically poled lithium niobate). In 1994, researchers at Southampton
published a key result using a novel approach which involved periodic
structuring using liquid electrodes [3.1] which produced the small periods
required with excellent fidelity, a result that followed soon after the
first reports from Sony in 1993 and Stanford University in 1994. Research
followed into the use of light to control periodic poling [3.2, G1, G3]
and fundamental work on structures within periodically poled materials was
undertaken via collaborative research [3.3] to further refine and
characterise all aspects of the final material precision and quality.
Progress in the underpinning research extended to the use of periodically
poled materials for efficient wavelength conversion into the blue (short
wavelength) where 450mW of blue light was generated [3.4] and
near-infrared (long wavelength) operation [3.5, G2] as well as the
adoption of optical waveguide technology which was developed in
conjunction with periodic poling [3.6] all of which presented further
opportunities to expand the range of future products. In particular, one
of the most commercially important contributions to the technology lay in
developing a simple process for periodic poling of magnesium oxide doped
crystals, which allows them to be used in high-power applications and at
In 2009, the spin-out company Covesion was founded by Professor Peter
G.R. Smith, who joined the Physics Department in 1994 as Research Fellow,
initially with just two staff members, to develop a PPLN business that
revolved around these new-generation magnesium oxide doped crystals.
Researchers who made significant contributions to this work include:
- Professor David Hanna, who instigated the research into periodic
poling technology, joined Physics department in 1983, Deputy Director of
the Optoelectronics Research Centre —ORC-from 1989 until his retirement
- Professor Robert Eason, who worked in the area of lithium niobate
material science from the late 1990s, joined Physics department in 1989,
Deputy Director of the ORC since 2007.
- Professor Peter G.R. Smith, founder of Covesion, joined the Physics
Department in 1994 as Research Fellow.
- Dr Graeme Ross, who joined the Physics Department as a PhD student in
1990, and continued as Research Fellow until 1998.
- Dr Corin Gawith, joining the ORC in 1998, and now CTO of Covesion,
- Dr Huw Major, a former PhD student who is now senior engineer at
References to the research
(best 3 are starred)
*[3.1] Webjörn, J., Pruneri, V., Russell, P.St.J., Barr, J.R.M. and
Hanna, D.C. (1994) Quasi-phase-matched blue light generation in bulk
lithium niobate, electrically poled via periodic liquid electrodes.
Electronics Letters, 30, (11), pp. 894-895.
[3.2] P.T. Brown, G.W. Ross, R.W. Eason, A.R. Pogosyan (1999) Control of
domain structures in lithium tantalate using interferometric optical
patterning, Optics Communications, Volume 163, Issues 4-6, pp. 310-316.
[3.3] Z. H. Hu, P. A. Thomas, A. Snigirev, I. Snigireva, A Souvorov, P.
G. R. Smith, G. W. Ross, S. Teat (1998) Phase-mapping of periodically
domain-inverted LiNbO3 with coherent X-rays, Nature 392, pp. 690-693 (16
*[3.4] G.W. Ross, M. Pollnau, P.G.R. Smith, W.A. Clarkson, P.E. Britton,
D.C. Hanna (1998), Generation of high-power blue light in periodically
poled LiNbO3, OPTICS LETTERS Volume: 23, Issue: 3, pp. 171-173.
*[3.5] M.A. Watson, M.V. O'Connor, P.S. Lloyd, D.P. Shepherd, D.C. Hanna,
C.B.E. Gawith, P.G.R. Smith, O. Blachninaite (2002), Extended operation of
synchronously pumped optical parametric oscillators to longer idler
wavelengths, OPTICS LETTERS Volume: 27, Issue: 23, pp. 2106-2108.
[3.6] L. Ming, C.B.E. Gawith, K. Gallo, M. O'Connor, G.D. Emmerson,
P.G.R. Smith (2005) High conversion efficiency single-pass second harmonic
generation in a zinc-diffused periodically poled lithium niobate
waveguide, OPTICS EXPRESS Volume: 13 , Issue: 13, pp 4862-4868.
Underpinning research grants
The research was funded by grants from EPSRC between 1994 and 2011, as
detailed below. Funding specifically attributable to PPLN research was
approximately £480,000, and funding was also provided via larger portfolio
grants [G4, G5, G6].
[G1] GR/K28251/01, OPTICALLY INDUCED PERIODIC DOMAIN GRATINGS, R.W.
Eason, 26/9/1994 to 25/9/1996, £103,506.
[G2] GR/M40301/01, NEW QUASI PHASE MATCHED NONLINEAR MATERIALS AND THEIR
APPLICATION TO OPTICAL PARAMETRIC OSCILLATORS, D.C. Hanna, P.G.R. Smith,
01/10/1998 to 31/03/2002, £196,437
[G3] GR/S47373/01, Light-induced domain engineering in ferroelectrics: a
route to sub-micron poling, R.W. Eason, 1/10/2003 to 30/9/2004, £152,050
[G4] GR/M81854/01 Advanced optical fibre and waveguide devices and
microstructured optical materials, EPSRC, DN Payne, DC Hanna, RW Eason, JS
Wilkinson, WS Brocklesby, E Taylor, HN Rutt, D Hewak, PGR Smith, M Zervas,
1/10/1999 -30/9/2003, £2,056,683.
[G5] GR/T11746/01 Fabrication of Microstructured Glass & Crystal
Photonic Materials & Devices, EPSRC, DN Payne, DC Hanna, RW Eason, JS
Wilkinson, PG Kazansky, T Monro, HN Rutt, DJ Richardson, D Hewak, DP
Shepherd, PGR Smith, 1/4/2004. Subsumed into Portfolio Partnership in
Photonics, 30/9/2004, £2,741,404.
[G6] EP/C515668/1 Portfolio Partnership in Photonics, EPSRC, DN Payne, WA
Clarkson, RW Eason, D Hewak, N Broderick, PGR Smith, 1/10/2004 -
Details of the impact
The process (from research to impact)
The spin-out company Covesion was itself spun out from a parent company,
Stratophase (another spin-out of the University started 2003), in 2009, to
better focus on research and development of its nonlinear optical
materials product line [5.1]. Following the first sales of PPLN to
GEC-Marconi, PPLN research has developed into a successful commercial
venture since the formation of the separate company Covesion. With fresh
venture capital investment, Covesion developed new Intellectual Property
around poling of MgO-doped PPLN for high power applications, technology
that had been pioneered at Southampton. At its inception Covesion
comprised only the two former Stratophase staff members working on PPLN.
Since then it has created five high-tech jobs and achieved sales worth
£2.1million over three years, 95 per cent of these sales being to overseas
customers [5.2, 5.3].
Covesion customers include some of the world's most successful companies
and prestigious research institutes, including some University-based
former PPLN research groups, not all of which can be named explicitly
here, for reasons of confidentiality, but span the areas of defence,
communications, laser manufacturing and medicine. New business has
therefore been created. The list includes major corporations such as
[text removed for publication]. [5.2]. From recent measurements of the
performance of these nonlinear engineered crystals, where 45W of green
light has been generated from an input near-infrared laser beam,
[reported by Stanford University, in 2012 [5.4] it is clear that
high-power lasers can now be built in a far more cost-effective manner
using Covesion components, and such impressive results have led to further
patent activity [5.5].
Another area that demonstrates economic impact relates to the use
of these engineered crystals in laser projection systems for presentations
and displays that have brighter, clearer colours but which use less energy
than conventional light bulb-based units, and therefore represents an
activity that has an impact on the environment also (management of
energy). Consumer demand in this area is growing rapidly, as
products are marketed for home cinema, desktop projectors and
rear-projection. Future opportunities are projectors integrated into
mobile phones and laptops, as well as use in medical screening and aero
defence equipment. Covesion has entered into a license agreement and
technology transfer programme with a leading projector company, [text
removed for publication]. [5.2].
The final claim under economic impact is that the crystals sold by
Covesion are essential parts of new laser systems and applications, which
has a significant value to global trade. The crystals are integrated into
high-end products which are sold by Covesion customers, so the leverage
effect is considerable, and vital to the success of these companies. The
company's own analysis of sales of these systems and the volume of
products shipped suggests that the total worldwide market value of
Covesion-enabled commerce is greater than US$25m per year (hence US$100m
since 2009) [5.2]. A ready example concerns Covesion products that are
used in short-pulse fibre lasers which are sold by at least three
manufacturers. Publicised users to date include Oclaro Inc., one of the
world's largest suppliers of optical communications equipment, the
world-leading universities Harvard and Stanford and leading governmental
research organisations such as NASA.
Other key applications for Covesion products lay in the area of medical
imaging, where 2-photon fluorescence microscopy that uses Covesion
crystals enables imaging of living tissue, an area of immediate concern
for real-time medical diagnostics. Covesion have also played a key role in
the consortium working on the EU-funded CROSS TRAP (Coherently-enhanced
Raman One-beam Standoff Spectroscopic Tracing of Airborne Pollutants)
project [5.6], which addresses the development of a novel laser remote
sensing technique for probing air at a distance for hazards such as
biochemicals, bacterial threats and explosive materials. Both of these
areas fall under the heading of new diagnostics for medical
A final area which falls under the heading of quality of life impact,
concerns the impact on society through provision of essential components
in systems that protect the public and armed forces of several nations — preventing future loss of life. Under UK export licenses, Covesion
crystals are used as wavelength conversion components in laser
countermeasure systems on over 90 commercial aircraft [5.2]. These involve
directing laser beams towards an approaching missile, causing it to veer
off course. [text removed for publication]. [5.7].
In conclusion, for the sake of completeness, a reference has been
included that describes global impact from the technical viewpoint, which
provides a list of publications from Covesion customers [5.8].
Sources to corroborate the impact
5.2 Contact to confirm sales figures, details on Projector license and
[text removed for publication]: COO of Covesion Limited
5.5 Southampton has applied for the following US patents: No. 8,064,129
(Process for poling a ferroelectric material doped with a metal), filed
2009, issued 2011, No. 8,054,536 (Electric field poling of ferroelectric
materials), filed 2008, issued 2011, 2011/0064,719, filed 2009
(Compensation for the Gouy phase shift in quasiphase matching), pending.
Contact: Knowledge Transfer Scheme Collaboration Manager, University of
5.7 [text removed for publication]
5.8 References to impact globally in technical terms (providing a list of
peer review publications by customers)http://www.covesion.com/news/