Widely Tunable Dual‐Wavelength Spacing via Temperature Control in A Single Self‐Assembled Nanowire‐Well Chip With Stress Modification

Abstract

ABSTRACT Dual‐wavelength single‐chip laser sources not only provide multiparameter measurement, but also provide a promising approach for terahertz (THz) signal generation. THz emission relies on the wavelength (or frequency) difference between dual lasing. Wide tunability of the dual‐wavelength difference, therefore, enables widely tunable THz signals for more flexible applications. In this paper, we propose a simple approach and mechanism for achieving dual‐wavelength emission with a widely tunable center‐wavelength spacing on a single chip via unified temperature control. It is based on an InGaAs self‐assembled nanowire‐quantum well composite structure with laterally periodic nanowire‐well and pure‐well parts contributing to dual‐wavelength emission. Due to distinct stress conditions in the two parts, their emission peaks exhibit markedly different temperature‐dependencies. As the temperature increases from 289 K to 321 K, the emission peak of the nanowire‐well part only varies from ∼930.6 to ∼931.8 nm (Δ ≈ 1.2 nm), while that of the pure‐well part shows a pronounced redshift from ∼963.8 to ∼985.7 nm (Δ ≈ 21.9 nm). Consequently, the dual‐wavelength spacing expands from ∼33.2 to ∼53.9 nm (Δ ≈ 20.7 nm), corresponding to a tuning rate of ∼0.65 nm/K. This research holds significant importance for enhancing the dynamic‐adaptability and compactness of dual‐wavelength semiconductor lasers for advanced applications.