Nanoscale coherent light sources are sought after as biological probes^[1] and as active components for photonic integrated circuits^[2]. Semiconductor Nanowires lasers (NWs) are well suited to this integration^[3]; and provide diverse emission properties, arising from the wide choice of materials, whilst being united in their fundamental operating principle of the nanowire forming a monolithic cavity and gain material. However, this leads to a deterministic relationship between cavity, material and performance that results in no two NWs performing the same way^[4]. This makes it difficult to scale-these devices up for applications that require high-yield and has made a reliable comparison study between different types of NWs a particular challenge.

We address these difficulties using automated optical microscopy to study 9 different NWL designs with 9 independent experiments^[5], to measure the dimensions, bandgaps, carrier recombination lifetimes, lasing thresholds, wavelengths and coherence lengths of >50,000 NWs in total [Figure 1a-d]. This facilitates a statistically rigorous comparison of the performance of each type of NW [Figure 1e]. 

We use this approach to determine the best-in-class NWs and demonstrate that the behaviour of these champion devices is not representative of the NW population. This traditional approach for inter-class comparison is therefore ambiguous. Additionally, by combining the datasets for all types of NWs, we confirm the long-standing prediction that the length and reflectivity of the NW cavity are the most important factors controlling the lasing threshold for any type of NW^[6]. This therefore elucidates a route towards achieving homogeneous performance across a population of all NWs.

[1]    X. Wu et al, “Nanowire lasers as intracellular probes”, Nanoscale, 2018, 10, 9729.

[2]    J. Yang et al, “From past to future: on-chip laser sources for photonic integrated circuits”, Light: Science & Applications, 2023,12, 1.

[3]    S. W. Eaton et al, “Semiconductor nanowire lasers”, Nature Rev. Mat., 2016, 1, 16028.

[4]    S. A. Church et al, “Optical characterization of nanowire lasers”, Prog. In Quant. Elec., 2022, 100408.

[5]    S. A. Church et al, “Holistic Nanowire Laser Characterization as a Route to Optimal Design”, Adv. Optical Mat., 2023, 2202476.

[6]    A. Maslov and C. Ning, “Reflection of guided modes in a semiconductor nanowire laser”, Appl. Phys. Lett., 2003, 83, 1237.