Periodic Reporting for period 1 - QuaLIDAD (Quantum cascade laser LIDar Advanced Device)
Reporting period: 2021-09-01 to 2023-02-28
The QuaLIDAD Project starts from the studies on Quantum Cascade Lasers (QCLs) performed within the EU Qombs Project. In Qombs, QCLs have been studied as emitters of low-phase-noise mid-infrared (IR) radiation for open-field communication and innovative LIDAR (LIght Detection And Ranging) schemes. The QuaLIDAD Project aims to exploit these results by developing a new compact and portable LIDAR system for remote in-field sensing of air pollution and range finding.
In its traditional implementation, a LIDAR retrieves range-resolved information by using pulsed visible or near-IR laser sources, with high peak power and short duration, through time resolved detection of the return signal. Our idea is to move the LIDAR operation in the mid-IR region, using continuous-wave QCLs operated with the Pseudo-Random Modulation (PRM) technique.
Moving at long infrared wavelengths has a double motivation. At first, mid-IR radiation is less affected by particle backscattering than radiation at shorter wavelengths, and this allows to solve the problems of poor operation under low-visibility conditions, e.g. related to the presence of fog, smoke, dust and other effects degrading the vision at short wavelengths. At the same time, the presence of atmospheric high-transparency windows allows the beam to propagate over long distances. Second, the mid-IR is the molecular fingerprint region, and the presence of strong absorptions from many pollutant molecules makes the system suitable also for air quality analysis.
Given this variety of applications, a mid-IR LIDAR can have a strong impact on society, from security and self-driving systems to air quality analysis, environmental control and athmospheric studies.
The final goal of the Project is the development and test of a portable LIDAR prototype working in the mid-IR spectral region, based on a cw QCL and on the PRM technique. This has been achieved by the following steps:
- design and acquisition of the optical components, in particular the laser, the detector and the required collimating and focusing optics;
- design, development and test of custom electronic Control Unit, capable of driving the QCL with a high-frequency PRM code, and including a digital comparator for the collected signal and a storage unit for the acquired data;
- setup of the LIDAR system, characterization and test of the PRM code, validation of the LIDAR with laboratory tests and outdoor measurements.
In its traditional implementation, a LIDAR retrieves range-resolved information by using pulsed visible or near-IR laser sources, with high peak power and short duration, through time resolved detection of the return signal. Our idea is to move the LIDAR operation in the mid-IR region, using continuous-wave QCLs operated with the Pseudo-Random Modulation (PRM) technique.
Moving at long infrared wavelengths has a double motivation. At first, mid-IR radiation is less affected by particle backscattering than radiation at shorter wavelengths, and this allows to solve the problems of poor operation under low-visibility conditions, e.g. related to the presence of fog, smoke, dust and other effects degrading the vision at short wavelengths. At the same time, the presence of atmospheric high-transparency windows allows the beam to propagate over long distances. Second, the mid-IR is the molecular fingerprint region, and the presence of strong absorptions from many pollutant molecules makes the system suitable also for air quality analysis.
Given this variety of applications, a mid-IR LIDAR can have a strong impact on society, from security and self-driving systems to air quality analysis, environmental control and athmospheric studies.
The final goal of the Project is the development and test of a portable LIDAR prototype working in the mid-IR spectral region, based on a cw QCL and on the PRM technique. This has been achieved by the following steps:
- design and acquisition of the optical components, in particular the laser, the detector and the required collimating and focusing optics;
- design, development and test of custom electronic Control Unit, capable of driving the QCL with a high-frequency PRM code, and including a digital comparator for the collected signal and a storage unit for the acquired data;
- setup of the LIDAR system, characterization and test of the PRM code, validation of the LIDAR with laboratory tests and outdoor measurements.
Within the 18 months of duration of the project, CNR and ppqSense worked in tight connection to develop both the optical assenbly and the electronic system, and to perform the LIDAR validation.
The work carried out during the Project period can be resumed as follows:
• Design of the LIDAR architecture, based on previous expertise of the CNR research team, and acquisition of the optical components (QCL, detector, paraboloidal reflectors);
• Design of the Control Unit, based on the expertise of ppqSense, and acquisition of the required electronic components;
• Integration of the QCL into the basic version of the Control Unit; QCL beam characterization and assembly of the optical system for laser collimation;
• Test of square wave amplitude molulation of the QCL: study of the laser response to different modulation frequencies and modulation depths;
• Optimization of the electronic board for the laser modulation, programming of the board for gold code modulation;
• Test of the QCL with gold code modulation, selection of the optimal working point of the QCL and selection of the optimal depth for the amplitude modulation;
• Assembly and alignment of the telescope for collection of backscattered light; assembly of the acquisition system, signal comparator and data storage;
• Test of the LIDAR operation with targets at different distances in the laboratory;
• Outdoor test of the LIDAR operation over hard obstacles at different distances.
The Project led to two main exploitable results:
• Development of an electronic Control Unit for high-frequency modulation of mid-IR cw QCLs with digital codes. The Unit was tested with square waves and gold code, but can work with any digital code.
• Development of a LIDAR system operating in the mid infrared spectral region, based on cw QCLs and on the PRM technique, suitable for both range finding and air quality monitoring.
The dissemination activities started during the Project will continue also after the end of the reporting period, and include:
• Release of the QuaLIDAD Website (www.qualidad-project.eu). The website is made of several different pages presenting the project and the team, and showing some demonstrative videos of the LIDAR outdoor operation.
• Practical demonstrations and promotion activities. Apart from the videos included in the website, practical demonstrations have been carried our during the outdoor tests. Further practical demonstrations are scheduled in the context of public openings of the University Campus during the summer. The activity and the LIDAR results have also been presented in dedicated meetings with visiting professors from other EU universities and research centers, during meetings dedicated to industrial innovation with industrial companies and in two EDA Captechs for Optronics.
• Communications to conferences: contributions on the project results have already been submitted to dedicated conferences to be held in the next months (SPIE ESI23, CLEO Europe 2023).
The work carried out during the Project period can be resumed as follows:
• Design of the LIDAR architecture, based on previous expertise of the CNR research team, and acquisition of the optical components (QCL, detector, paraboloidal reflectors);
• Design of the Control Unit, based on the expertise of ppqSense, and acquisition of the required electronic components;
• Integration of the QCL into the basic version of the Control Unit; QCL beam characterization and assembly of the optical system for laser collimation;
• Test of square wave amplitude molulation of the QCL: study of the laser response to different modulation frequencies and modulation depths;
• Optimization of the electronic board for the laser modulation, programming of the board for gold code modulation;
• Test of the QCL with gold code modulation, selection of the optimal working point of the QCL and selection of the optimal depth for the amplitude modulation;
• Assembly and alignment of the telescope for collection of backscattered light; assembly of the acquisition system, signal comparator and data storage;
• Test of the LIDAR operation with targets at different distances in the laboratory;
• Outdoor test of the LIDAR operation over hard obstacles at different distances.
The Project led to two main exploitable results:
• Development of an electronic Control Unit for high-frequency modulation of mid-IR cw QCLs with digital codes. The Unit was tested with square waves and gold code, but can work with any digital code.
• Development of a LIDAR system operating in the mid infrared spectral region, based on cw QCLs and on the PRM technique, suitable for both range finding and air quality monitoring.
The dissemination activities started during the Project will continue also after the end of the reporting period, and include:
• Release of the QuaLIDAD Website (www.qualidad-project.eu). The website is made of several different pages presenting the project and the team, and showing some demonstrative videos of the LIDAR outdoor operation.
• Practical demonstrations and promotion activities. Apart from the videos included in the website, practical demonstrations have been carried our during the outdoor tests. Further practical demonstrations are scheduled in the context of public openings of the University Campus during the summer. The activity and the LIDAR results have also been presented in dedicated meetings with visiting professors from other EU universities and research centers, during meetings dedicated to industrial innovation with industrial companies and in two EDA Captechs for Optronics.
• Communications to conferences: contributions on the project results have already been submitted to dedicated conferences to be held in the next months (SPIE ESI23, CLEO Europe 2023).
The technological achievements of QuaLIDAD goes beyond the state of the art in two main points, reflecting the main exploitable results of the Project:
1) development of a modular electronic driving unit able to drive QCLs with custom modulation signals, including Pseudo-Random Codes, at RF frequencies of tens of MHz. The unit includes the a module dedicated to the temperature stabilization and a module dedicated to the current supply of the QCL, a FPGA unit dedicated to the modulation of the laser and to the acquisition, averaging and storage of the detected signal, and a digital comparator.
2) developemt and test (indoor and outdoor) of a LIDAR operating in the mid infrared, based on cw QCLs and on the Pseudo-Random Modulation technique, suitable for both range finding of remote obstacles and air-quality analysis through path-integrated chemical analysis.
The Project impacts both applied research on QCL sources and Earth studies and the sector of sensing technology for civil and military use.
In particular, the Project results strengthen the Qombs Project outcomes, represent an innovation and the success of the validation tests has the potentiality to contribute to expanding both the QCLs market and the industry of sensors for remote detection of obstacles and for air quality analysis. This impacts the fields of climate studies, disease prevention in urban or industrial contexts, robotics technology, autonomous systems, self-driving cars, and other applications in both the military and civil contexts especially related to the possibility of improved vision under low-visibility conditions.
1) development of a modular electronic driving unit able to drive QCLs with custom modulation signals, including Pseudo-Random Codes, at RF frequencies of tens of MHz. The unit includes the a module dedicated to the temperature stabilization and a module dedicated to the current supply of the QCL, a FPGA unit dedicated to the modulation of the laser and to the acquisition, averaging and storage of the detected signal, and a digital comparator.
2) developemt and test (indoor and outdoor) of a LIDAR operating in the mid infrared, based on cw QCLs and on the Pseudo-Random Modulation technique, suitable for both range finding of remote obstacles and air-quality analysis through path-integrated chemical analysis.
The Project impacts both applied research on QCL sources and Earth studies and the sector of sensing technology for civil and military use.
In particular, the Project results strengthen the Qombs Project outcomes, represent an innovation and the success of the validation tests has the potentiality to contribute to expanding both the QCLs market and the industry of sensors for remote detection of obstacles and for air quality analysis. This impacts the fields of climate studies, disease prevention in urban or industrial contexts, robotics technology, autonomous systems, self-driving cars, and other applications in both the military and civil contexts especially related to the possibility of improved vision under low-visibility conditions.