Periodic Reporting for period 1 - OPTAPHI (European Joint Doctorate Programme on Optical Sensing using Advanced Photo-Induced Effects)
Reporting period: 2020-01-01 to 2021-12-31
Due to Europe's strong activity in optical sensing and the large variety of applications, it is becoming increasingly difficult for all sectors to find highly skilled photonics graduates, particularly at the interfaces between sectors. In particular, optical sensing is intrinsically a multi-disciplinary topic, requiring expertise in chemistry, physics and engineering, making truly disruptive innovation difficult within a traditional Ph.D. project. The OPTAPHI network (pronounced opta-fy) aims to address this by training a cohort of doctoral students in the complementary fields of advanced spectroscopy and integrated optics. Specifically, the focus is on the methods of photo-acoustic and photo-thermal spectroscopy, and the compact semiconductor lasers and integration techniques that enable sensors based on these.
Within OPTAPHI, 14 Early Stage Researchers will be enrolled in Double Doctorate degree programmes, studying at, and being awarded Ph.D. degrees from, two of the partner institutes. The training from leading research groups will be complemented by secondment opportunities offered by ten associated Partner Organisations, together with network-wide training events such as workshops and a summer school. Overall scientific objectives include;
- Demonstrate novel Quartz Enhanced Photo-Acoustic Spectroscopy (QEPAS) and Photo-Thermal Spectroscopy (PTS) configurations with improved sensitivity and compactness
- Demonstrate improved detection of benzene, toluene, ethylbenzene and xylene (BTEX) and propane exploiting long wavelength 10+ μm laser sources
- Demonstrate highly sensitive Photo-Thermal Spectroscopy for liquid analysis for the first time Improve the compactness, robustness and power consumption of QEPAS to allow use on Unmanned Aerial Vehicles
- Demonstrate new methodologies to improve the sensitivity of PTS and QEPAS in the second overtone band, thereby allowing the use of low-cost telecoms components
Each Fellow has established a Personal Career Development Plan, and completed a 9-month progress review report. A project website was established at www.optaphi.eu and a Twitter account, @optaphi. A number of flyers and a full 26-page prospectus were prepared as part of the recruitment advertising, and a pull-up banner was produced for use at events.
WP1: Environmental Sensing
The main goal of WP1 is the realisation of a portable demonstrator to showcase the potential of the OPTAPHI technologies for high-sensitivity detection of a number of gases important for the environment, such as BTEX, methane, CO, CO2, N2O, etc. Several different laser technologies and sensing approaches are being developed by 5 ESRs, including; compact diode-laser based QEPAS for UAVs; long-wavelength PTS for BTEX detection; hybrid photonic crystal lasers for intra-cavity QEPAS and PTS; Long wavelength QCLs for BTEX and propane detection through QEPAS; and generation and detection of photo-thermal and photo-acoustic waves in solids for advanced near-field IR imaging.
WP2: Agri-Food Analysis
The goal of this workpackage is the realisation of a shoe-box sized demonstrator PTS and/or QEPAS sensor capable of monitoring the quality of foods. As target gas analytes, basic amines (in particular ammonia) as an indicator for food degradation (fish) as well as diacetyl as a quality parameter for brewing have been chosen. The 4 ESR projects within WP2 are: ultra-compact QEPAS by integrating cantilever hybrid laser with quartz tuning fork; QEPAS and PTS using low-cost telecoms wavelength lasers for food analysis; High Q factor Photonics Cavities for PTS; and Intracavity PTS with optical feedback for isotopic verification of food origin.
WP3: Industrial Process Monitoring
The main goal of WP3 is the realisation of highly performant, innovative and compact sensing systems to be used for monitoring industrial processes. Sensing approaches like intra-cavity QEPAS for highly sensitive target gas measurements or PTS for detection of water in organic solvents will be developed. At the same time, improvement in the laser sources will be pursued by realising novel hybrid laser and single mode interband cascade lasers.
The ESRs have progressed well towards these targets, achieving different levels of maturity on both the laser and sensing aspects, depending on the starting TRL of the technology. This has included the design, fabrication and testing of a number of different laser devices, as well as building and optimising several lab-based spectroscopy setups. A total of 16 journal articles and 2 conference papers related to OPTAPHI have been published, including 2 papers with an OPTAPHI ESR as first author.