Quantum Dot Breakthrough Makes Infrared Lasers Affordable and Scalable

By ICFO-The Institute of Photonic Sciences December 13, 2024

Collected at: https://scitechdaily.com/quantum-dot-breakthrough-makes-infrared-lasers-affordable-and-scalable/

Researchers have developed a new laser technology using large colloidal quantum dots of lead sulfide to emit coherent light in the extended short-wave infrared range.

This innovation promises cheaper, scalable laser solutions compatible with silicon CMOS platforms, covering a broader wavelength range without altering chemical compositions, and eliminating the need for costly femtosecond laser amplifiers.

Novel Laser Technologies

Current laser technologies for the extended SWIR spectral range depend on costly and complex materials, making them difficult to scale and less affordable. To overcome these limitations, a team of ICFO researchers, led by ICREA Prof. Gerasimos Konstantatos, developed a novel solution using colloidal quantum dots (CQDs). Their findings, published on December 6 in Advanced Materials, demonstrate that large lead sulfide (PbS) CQDs can emit coherent light—a key requirement for creating lasers—in the extended short-wave infrared (SWIR) range.

This breakthrough addresses the challenges of cost and scalability while remaining compatible with silicon CMOS platforms, the standard technology used in building integrated circuit chips. This compatibility opens the door to seamless on-chip integration, paving the way for more practical and accessible laser applications.

Advancements in Quantum Dot Lasers

Their PbS colloidal quantum dots are the first semiconductor lasing material to cover such a broad wavelength range. Remarkably, the researchers accomplished this without altering the dots’ chemical composition. These results pave the way toward the realization of more practical and compact colloidal quantum dots lasers.

Further to that, the team demonstrated lasing – for the first time in PbS quantum dots – with nanosecond excitation, replacing the need for bulky and costly femtosecond laser amplifiers. That was achieved by employing larger quantum dots, increasing thus the absorption cross-section of the dots tenfold, leading to a dramatic reduction in the optical gain threshold –the point at which the laser light emission becomes an efficient process.

Potential Applications and Future Implications

The ability to produce low-cost, scalable infrared lasers in the extended SWIR range addresses critical bottlenecks in various technologies. This innovation has transformative potential for diverse applications, including hazardous gas detection, eye-safe LIDAR systems, advanced photonic integrated circuits, and imaging within the SWIR biological window.

Industries relying on LIDAR systems, gas sensing, and biomedicine could greatly benefit from this cost-effective and integrable solution. Moreover, this breakthrough supports the transition to silicon-compatible photonic integrated circuits, enabling greater miniaturization and widespread adoption.

Paradigm Shift in Laser Technology

“Our work represents a paradigm shift in infrared laser technology,” said ICREA Prof. Gerasimos Konstantatos. “For the first time, we’ve achieved lasing in the extended SWIR range with solution-processed materials at room temperature, paving the way for practical applications and the development of more accessible technologies.”

Reference: “Extended Short-Wave Infrared Colloidal Quantum Dot Lasers with Nanosecond Excitation” by Guy L. Whitworth, Carmelita Roda, Mariona Dalmases, Nima Taghipour, Miguel Dosil, Katerina Nikolaidou, Hamed Dehghanpour and Gerasimos Konstantatos, 6 December 2024, Advanced Materials.
DOI: 10.1002/adma.202410207