Elevated expectations for laser performance, encompassing broadband tunability, integration, low power consumption, and a low threshold, have emerged within the realms of photonic chips and optoelectronic devices. Nevertheless, achieving multicolor miniaturized lasers within a singular micro-nano structure remains challenging, hindered by constraints in geometric structure, optical gain, and bandgap considerations. Here, we propose an approach to obtain integrated multicolor lasing beams output simultaneously in a desired direction from a two-dimensional constrained micro-resonator. The wavelength of the lasing beam is tuned by controlling the size of quantum dots (QDs) in the resonator. Owing to the high density of power within the cavity and the localized surface plasmon resonance on the surface of the Au-Ag nanowires (NWs), a notably low laser threshold is realized in the micro-resonator channel.

Figure 1. (a) Vision of our integrated chip: achieving simultaneous red, green, and blue lasing outputs from the MCR, with each color independently transferred via an optical fiber. (b) Schematic of integrated RGB lasing utilizing our chip. (c) Schematic diagram of MCR laser. (d) The distribution of electric field intensity in the MCR at the excitation wavelength of 355 nm.

Figure 2. The lasing of the CdSe QDs and Au-Ag NWs in MCR.

We proposed a 2D constrained semiconductor quantum dot integrated micro-laser, comprising a multichannel MCR and Au-Ag NWs, achieves multicolor directional output and low-threshold CdSe QDs lasing. The Au-Ag NWs contribute to multiple scattering feedback and local plasmon resonance enhancement. The MCR provides a high density of power oscillating field, enhancing the interaction between CdSe QDs and pump light and facilitating stimulated emission at a low threshold. By controlling the number of channels in which the MCR is excited, we can individually or simultaneously output red, green, blue, cyan, yellow, purple, and white lasers. This multicolor integrated micro-laser supports the realization of active photonic chips.

This research is published in “Meng Zhang, Hailang Dai, Yanbo Zhao, and Xianfeng Chen, Miniaturization of multicolor quantum dots lasing based on two-dimensional constrained resonator, Advanced Optical Materials, 2400017 (2024)”.

Link: https://onlinelibrary.wiley.com/doi/10.1002/adom.202400017