Four‐Dimensional Design Space of High‐Q Second‐Order Distributed Feedback Perovskite Lasers

Abstract

Second‐order distributed feedback (DFB) resonators are widely used for thin‐film lasers as they combine low lasing thresholds with ease of manufacturing. Here, the grating design parameters are varied to map the lasing characteristics of lead halide perovskite films deposited on a single substrate that contains hundreds of high‐quality silicon nitride surface gratings. The lowest lasing threshold (≈130 µJ cm−2) is identified through the aid of near‐field and far‐field imaging spectroscopy in a four‐dimensional design space composed of grating period, duty cycle, active layer thickness, and cavity length. Moreover, it is shown that antisymmetric modes support high‐quality lasing (Q up to ≈10800) in the second‐order DFBs. The multi‐dimensional experimental analysis is accompanied by a thorough theoretical study with a semi‐empirical model based on coupled wave equations, which is used to investigate the lasing characteristics beyond the manufacturing range. The results can be applied to a broad range of thin‐film DFB resonators, enabling the design of more complex laser stack configurations including light‐emitting devices for current‐injection lasing.