A pioneering research effort highlights a major leap forward in laser technology, offering more cost-effective and scalable options for uses that include environmental monitoring and biomedical imaging. Scientists have crafted the first laser that utilizes colloidal quantum dots (CQDs), which can function across the entire extended short-wave infrared (SWIR) spectrum.
Traditional laser technologies that operate in the extended SWIR range typically depend on expensive and intricate materials, which restricts their scalability and affordability. To tackle these issues, a team led by ICREA Professor Gerasimos Konstantatos at ICFO, including researchers Dr. Guy L. Withworth, Dr. Carmelita Roda, Dr. Mariona Dalmases, Dr. Nima Taghipour, Miguel Dosil, Dr. Katerina Nikolaidou, and Hamed Dehghanpour, has put forward an innovative method utilizing colloidal quantum dots in an article published in Advanced Materials. They successfully generated coherent light (a key requirement for laser creation) in the extended SWIR spectrum using large colloidal quantum dots made of lead sulfide (PbS).
The CQD technology introduced here effectively overcomes the previously mentioned obstacles while remaining compatible with silicon CMOS platforms (the technology employed for building integrated circuit chips), facilitating on-chip integration.
These PbS colloidal quantum dots represent the first semiconductor material capable of lasing over such a wide array of wavelengths. Remarkably, the researchers achieved this milestone without modifying the chemical makeup of the dots. This achievement paves the way for the development of smaller, more efficient colloidal quantum dot lasers. Additionally, the team successfully demonstrated lasing in PbS quantum dots for the first time using nanosecond excitation, eliminating the necessity for large and costly femtosecond laser amplifiers. This was accomplished by utilizing larger quantum dots, which enhanced the absorption cross-section of the dots tenfold, significantly lowering the optical gain threshold – the point at which the laser begins to efficiently emit light.
The creation of low-cost, scalable infrared lasers operating in the extended SWIR range alleviates critical constraints across various technologies. This innovation could revolutionize multiple fields, such as hazardous gas detection, eye-safe LIDAR systems, advanced photonic integrated circuits, and imaging within the SWIR biological window. Sectors that rely on LIDAR, gas sensing, and biomedicine stand to gain substantially from this affordable and integrable solution. Furthermore, this advancement promotes the transition to silicon-compatible photonic integrated circuits, allowing for more compact designs and broader implementation.
“Our research signifies a major breakthrough in infrared laser technology,” stated ICREA Prof. Gerasimos Konstantatos. “For the first time, we have achieved lasing in the extended SWIR range using solution-processed materials at room temperature, setting the stage for practical applications and the creation of more accessible technologies.”
