Tunable Narrowband Carbon Quantum Dots Laser Based on Self‐Assembled Microstructure

Abstract

Photonic integrated circuits (PICs) are coupled with the laser to create active devices for optical communication, optical interconnection, and optical computing. Consequently, the light source remains a focal point of extensive research and development. Currently, the utilization of carbon quantum dots as a gain medium in photonic cavity lasers is accomplished and suggested as a viable approach for achieving active PICs. Nevertheless, challenges persist in achieving narrowband lasing beam output in one direction that is real‐time tunable while minimizing energy losses. These issues represent an active area of ongoing research. This article presents a self‐assembled microstructure and proposes a method for obtaining tunable, narrowband, unidirectional lasing beams. The objective is to stimulate further development in integration of PICs with lasers, extending beyond these applications, to realize substantial performance gains, eco‐friendly solutions, and efficient mass production.

Statistically Identified Dual Type Random Lasing from Carbon Dots

“…41,42 Other works have rather demonstrated hybrid designs, where RL is observed from CDs hosted inside a microresonator under certain experimental conditions, 43 or scatterers 38 are utilized to reduce CD lasing threshold within a Fabry−Perot cavity. While lasing from CDs housed inside a square cuvette easily leads to directional laser beams, 44,45 it is often unclear if this emission can be classified as Fabry−Perot lasing off cuvette walls, which can provide remarkably strong feedback even without external mirrors, or rather RL enabled by scattering from CDs themselves. In general, discriminating true RL from other forms of laser amplification and pinpointing the transition from incoherent to coherent RL can be difficult tasks that can only be achieved by a thorough analysis of the statistical properties of the emitted light, by analyzing shot-by shot fluctuations of the narrowband emission, and by comparing the characteristics of the emissions in various pumping geometries.…”

“…In regard to lasers, although CD optical gain coefficients are generally smaller , than luminescent dyes, QDs, and perovskites, − CDs have been successfully used as gain media in traditional laser cavities. , However, CD-based random lasers remain challenging, since CDs are usually quenched by semiconductor or metal nanoscatterers. , Thus, only a few works have provided clear-cut evidence of paradigmatic mirror-free RL emission from a mixture of CDs and metal or semiconductor scatterers. , Other works have rather demonstrated hybrid designs, where RL is observed from CDs hosted inside a microresonator under certain experimental conditions, or scatterers are utilized to reduce CD lasing threshold within a Fabry–Perot cavity. While lasing from CDs housed inside a square cuvette easily leads to directional laser beams, , it is often unclear if this emission can be classified as Fabry–Perot lasing off cuvette walls, which can provide remarkably strong feedback even without external mirrors, or rather RL enabled by scattering from CDs themselves. In general, discriminating true RL from other forms of laser amplification and pinpointing the transition from incoherent to coherent RL can be difficult tasks that can only be achieved by a thorough analysis of the statistical properties of the emitted light, by analyzing shot-by shot fluctuations of the narrowband emission, and by comparing the characteristics of the emissions in various pumping geometries.…”