Traditionally, PICs have played a significant role in enabling advanced optical communication. However, Samu-Pekka Ojanen's work shifts the focus to their use in sensing applications, especially in the 2–4 µm wavelength range. This spectral region is crucial for detecting gases like methane and carbon dioxide, as well as important biomarkers, such as glucose and lactate. Traditional optical sensors have struggled with several limitations, including high cost, large size, high power consumption, and limited sensitivity. These drawbacks restrict their ability to provide real-time monitoring and precise detection in various applications.
“By integrating advanced laser technology into PICs, we can overcome the limitations of conventional sensors and achieve unprecedented sensitivity and accuracy,” Ojanen explains.
Ojanen's study introduces innovative hybrid lasers that combine GaSb-based III/V semiconductor materials with silicon and silicon nitride platforms, enabling them to detect specific gases with high sensitivity. This technology has the potential to create compact, low-cost sensors for real-time environmental monitoring.
“The prospect of deploying a vast network of these sensors could drastically improve our ability to monitor air quality and greenhouse gas emissions,” he says.
In healthcare, the hybrid lasers could revolutionize diagnostics by enabling non-invasive monitoring of biomarkers like glucose. This approach offers a more practical alternative to traditional blood tests, enhancing patient compliance and allowing for continuous monitoring.
"Non-invasive sensors could significantly improve patient outcomes by facilitating early disease detection and management," Ojanen notes.
Samu-Pekka Ojanen carried out his doctoral dissertation research at the Optoelectronics Research Centre (ORC) under the lead supervision of Professor Mircea Guina. His thesis was completed as part of the DSII program, benefiting from direct funding from Vaisala.
Public defence on Thursday 5 September
The doctoral dissertation of M.Sc. (Tech.) Samu-Pekka Ojanen in the field of photonics titled "Multiwavelength Photonic Integrated Lasers with Emission at 2–3 µm" will be publicly examined in the Faculty of Engineering and Natural Sciences at Tampere University on Thursday 5th September 2024 at 13:00 at Hervanta campus, in Festia building Pieni Sali 1, FA032 (Korkeakoulunkatu 8, Tampere).
The Opponent will be Doctor Borislav Hinkov from Silicon Austria Labs (Austria). The Custos will be Adjunct Professor Jukka Viheriälä from the Faculty of Engineering and Natural Sciences, Tampere University.
The doctoral dissertation is available online
The public defence can be followed via remote connection