Mid-Infrared GeRmAnium phoTonIcs fOr seNsing (MIGRATION)

Lead Research Organisation: University of Southampton
Department Name: Optoelectronics Research Centre

Abstract

Group IV photonics is a field that is currently revolutionizing the future of modern optoelectronic devices. So far most of the focus has been on silicon based materials at near-infrared wavelengths for use in data communications, though some more recent demonstrations in the 2-3um regime include Raman and parametric amplification. There are a number of advantages to extending the operational range of these devices into the mid-infrared regime such as lower optical losses and higher nonlinear coefficients, and preliminary device work in this area has shown improved efficiencies over their near-infrared counterparts. Moreover, this wavelength regime supports a host of important applications such as chemical and biological sensing, environmental and hazardous substance monitoring, medicine, and industrial process controls. The most efficient wavelength band for many of these applications is the so called 'fingerprint' region (>8um) where the precise identification of many molecular substances is possible. However, as the transparency of silicon only extends to ~8um, more recently attentions have been turning to germanium (transparency range 2-15um) as an alternative platform to fully realize the mid-infrared capabilities of group IV devices for sensing and other life science applications. Significantly, compared to silicon, germanium offers a number of other advantages in terms of device development such as even higher nonlinear coefficients, better carrier mobility, and the potential to realise active devices based on germanium based alloys.

The work in this programme proposes to lay the foundations for a migration of mid-infrared group IV photonics from silicon to germanium-based platforms with the aim to future proof emerging technologies in this field. Thus, one of the main outcomes of this work will be to identify high quality germanium substrates that rival the performance of the well-established silicon-on-insulator wafers used over the 1-3um regime; a task that will be performed in conjunction with our project partners IQE who are the UK's global leaders in advanced semiconductor wafer fabrication. This framework will then be used to demonstrate a library of devices such as waveguides, couplers, filters, amplifiers and modulators that will form the building blocks of integrated on-chip circuits, systems and sensors over an extended wavelength regime. Although the primary focus of this project is the development of integrated sensors for toxic detection with improved efficiency, compactness, and robustness, which are required for DSTL and other defence and security stakeholders, by targeting devices that can perform a range of basic functions, these will be relevant to a variety of applications ensuring maximal impact. This visionary programme of research is at the forefront of this exciting new area of mid-infrared group IV photonics and thus promises to deliver a number of disruptive mid-infrared photonics solutions.

Planned Impact

There is a high demand for sensors that are small, versatile and low cost for application in multi-billion dollar markets such as environmental monitoring, defence and security, medicine, and industrial process control. We believe that MIGRATION will be a catalyst for a series of research breakthroughs that will lead to the realisation of such sensors and result in significant economic and societal impact. This research is directly aligned with three of the main EPSRC themes.

Global Uncertainties: New emerging challenges from organised crime and terrorist groups underline the vital need for sensitive and selective, rapid (in field) identification of different types of chemical hazardous materials such as drug mixtures, chemical and biological warfare (CBW), explosives, and toxic spills. The platforms developed in the proposed work will enable realisation of compact chemical agent sensors with low false alarm rates. Such sensors would be of use for the protection of UK forces at home and abroad, by alerting them of the location of hazardous materials before they are encountered. Similarly, they could also be applied by first responders for the prevention terrorist attacks and in industrial accidents.

Healthcare Technologies: The high sensitivity of the systems that operate in the fingerprint wavelength region will also ensure that they can be applied in healthcare applications for efficient point of care diagnostics. For example, accurate breath tests can be used to detect diabetes and stomach cancer (http://www.bbc.co.uk/news/health-21671455), both of which give off signature smells of volatile organic compounds. Specifically, breath test trials are already being used to detect diabetes in children (http://www.bbc.co.uk/news/uk-england-oxfordshire-15589264), though we also expect such non-invasive tests to be important for care of our aging society.

Living with Environmental Change: In the longer term, these systems will be of use for networked environmental sensors to monitor pollutant concentration in air (e.g., CO2 emissions in cities), water, and soil. Extensive monitoring of developing cities and industrial estates will assist policy makers in determining how to create/maintain a healthier environment. In particular, the monitoring of water supplies for detection of biological outbreaks (deliberate or not) is critical for public health, as well as for services such as transport and power generation.

The new platforms proposed in this project have the potential to offer elegant solutions in each of these important areas, thus causing a migration in the Group IV photonics research community from silicon to germanium. As such, this research will be of wide interest as an enabling technology to both academic and industrial communities. The partnership with DSTL and IQE Silicon Ltd demonstrates the relevance of our proposal to UK industries, and especially the importance to maintain at the forefront of emerging mid-IR sensing technologies. Currently the UK is fourth in the world in terms of sensor production, with 60% of the production being exported, and we hope that this work will stimulate further growth in this area. In addition, by training new staff in this area we will ensure that the UK has a solid skill and knowledge base for any future industrial, as well as academic, developments.
 
Description We have developed several material platforms for silicon and germanium mid-infrared photonics. We have achieved world leading results for waveguiding, modulation, detection and non linear effects in Si and Ge at longer wavelengths, and reported novel structures with large potential for application in the mid-IR. For the first time, Ge on Si waveguides have been characterised at wavelengths as long as 9 microns and we have demonstrated first sensing experiments of toxic simulants in this wavelength range.
Exploitation Route The material platforms we have developed can be used by defense agencies and astronomers, in spectroscopy and in environmental sensing.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Digital/Communication/Information Technologies (including Software),Environment,Healthcare

URL http://www.orc.soton.ac.uk/migration.html
 
Description Our work and achieved results are very encouraging and have attracted an interest from our project partner DSTL. We are now working with them on the application of our material platforms for detection of toxic substances. They have also supported our 3 research bids. Our work has also attracted interest from a US based company Phase Photonics and we are in nagotiations with them about implementation of our spectrometers in real products. The developed platforms will also be offered to academia and industry in multi project wafers runs in the Southampton Nanofabrication Centre.
First Year Of Impact 2015
Sector Aerospace, Defence and Marine,Chemicals,Digital/Communication/Information Technologies (including Software),Environment
Impact Types Economic

 
Description New photonics modules in Southampton
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Influenced training of practitioners or researchers
Impact The project showed the potential of the realised photonics platforms and capability of our cleanroom in Southampton. As a result, new photonics modules at both undergraduate and postgraduate levels have been introduced in Southampton, with very strong practical elements in their syllabuses thus increasing the number of students with better skills in the field of photonics, and in particular in design, fabrication and characterisation of photonic devices.
 
Description KTA
Amount £49,850 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 07/2014 
End 07/2015
 
Description PhD studentship
Amount £77,680 (GBP)
Organisation University of Southampton 
Sector Academic/University
Country United Kingdom
Start 09/2017 
End 03/2021
 
Description PhD studentship
Amount £137,760 (GBP)
Organisation University of Southampton 
Sector Academic/University
Country United Kingdom
Start 09/2015 
End 03/2019
 
Description PhD studentship
Amount £137,760 (GBP)
Organisation University of Southampton 
Sector Academic/University
Country United Kingdom
Start 09/2016 
End 03/2020
 
Description PhD studentship
Amount £77,680 (GBP)
Organisation University of Southampton 
Sector Academic/University
Country United Kingdom
Start 09/2016 
End 03/2020
 
Description Platform grant
Amount £1,477,730 (GBP)
Funding ID EP/N013247/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 04/2016 
End 03/2021
 
Title Mask design 
Description Milos Nedeljkovic, employed on the grant has developed a method for rapid design of photonic integrated circuits, by writing software that can automatise mask design. 
Type Of Material Improvements to research infrastructure 
Year Produced 2015 
Provided To Others? Yes  
Impact It has been widely accepted in Southampton and several other groups have been using it. We have also offered it to other groups in the UK and also worldwide. 
 
Title Ge modulation modelling 
Description My team has developed a calculation model for predicting optical modulation in Germanium at various wavelengths and offered that to the research community. We have collected an extensive set of parameters published in the literature, extrapolated those to fill in some gaps and conducted rigorous theoretical analysis to develop the model. 
Type Of Material Computer model/algorithm 
Year Produced 2015 
Provided To Others? Yes  
Impact Various group around the world are now using this model to design germanium based photonic devices. 
 
Description Bari 
Organisation Polytechnic University of Bari
Department Dipartimento di Ingegneria Elettrica e dell'Informazione
Country Italy 
Sector Academic/University 
PI Contribution We have been working with the Bari team on Vernier configurations in silicon and germanium. We fabricated the devices and characterised them.
Collaborator Contribution The Bari team carried out the modelling part of the work.
Impact Several papers in high impact factor journals and at international and national conferences.
Start Year 2014
 
Description Collabortion with the University of Malaga, Spain 
Organisation University of Malaga
Country Spain 
Sector Academic/University 
PI Contribution We have fabricated and characterised novel photonic devices developed by Southampton and Malaga teams.
Collaborator Contribution The Malaga group have designed the devices and conducted a thorough theoretical investigation before the fabrication.
Impact 1 journal paper published, 1 journal paper submitted, 1 conference paper presented
Start Year 2014
 
Description McMaster 
Organisation McMaster University
Country Canada 
Sector Academic/University 
PI Contribution My team modelled and characterised devices fabricated by McMaster University.
Collaborator Contribution McMaster University fabricated photodetectors. The results were outstanding and were published in Nature Photonics.
Impact J. J. Ackert, D. J. Thomson, L. Shen, A. C. Peacock, P. E. Jessop, G. T. Reed, G. Z. Mashanovich, and A. P. Knights, "High-speed detection above the telecommunication windows with monolithic silicon photodiodes," Nature Photonics, vol. 9, pp. 393-396, 2015. D. J. Thomson, L. Shen, J. J. Ackert, E. Huante-Ceron, A. P. Knights, M. Nedeljkovic, A. C. Peacock, and G. Z. Mashanovich, "Optical detection and modulation at 2µm - 2.5µm in silicon," Optics Express, vol. 22, pp. 10825-10830, 2014.
Start Year 2014
 
Description Paris Sud 
Organisation University Paris Sud
Country France 
Sector Academic/University 
PI Contribution My team has fabricated and characterised devices based on modelling obtained by researchers from Paris Sud. Excellent results have been obtained and published in leading photonics journals.
Collaborator Contribution Researchers from Paris Sud conducted complex simulations that lasted several months of suspended Si structures and Ge-on-Si structures.
Impact C. Alonso-Ramos, M. Nedeljkovic, D. Benedikovic, J. Soler Penadés, C. Littlejohns, D. Pérez-Galacho, L. Vivien, P. Cheben, and G. Z. Mashanovich, "Germanium-on-silicon mid-infrared grating couplers with low-reflectivity inverse taper excitation," Optics Letters, vol. 41, pp. 4324-4327, 2016. J. Soler Penades, A. Ortega-Moñux, M. Nedeljkovic, J. G. Wangüemert-Pérez, R. Halir, A.Z. Khokhar, C. Alonso-Ramos, Z. Qu, I. Molina-Fernández, P. Cheben and G. Z. Mashanovich, "Suspended silicon mid-infrared waveguide devices with subwavelength grating metamaterial cladding," Optics Express, vol. 24, pp. 22908-22916, 2016.
Start Year 2015
 
Title Suspended Si 
Description In this project we have developed a new photonics material platform: suspended Si platform with metamaterial cladding. This new technology has several advantages compared to the previously reported approaches: it is more mechanically robust, easier to fabricate and have lower losses. 
Type Of Technology New/Improved Technique/Technology 
Year Produced 2016 
Impact It has attracted significant interest from the research community and several groups worldwide have adopted this approach. 
 
Description Group-IV material waveguides for mid-infrared sensing" EOSAM 2016 Workshop on "Sensing Applications Enabled by Silicon Photonics" Berlin, Germany, 26-30 September 2016. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Group-IV material waveguides for mid-infrared sensing - there was an interest from industry we are still involved in correspondence.
Year(s) Of Engagement Activity 2016