Advances in material, structural, and integration strategies for DFB lasers in photonic sensing platforms

III-V-based distributed feedback (DFB) semiconductor lasers are fundamental building blocks for integrated photonic sensing because of their single-mode operation, narrow linewidth, and spectral coverage. This review provides a comprehensive overview of III-V DFB lasers, beginning with a comparison of major material platforms—GaN, GaAs, InP, GaSb, and quantum cascade laser (QCL) structures—across the visible to mid-infrared spectrum. We then highlight two main avenues of innovation: the use of quantum dot (QD) gain media for enhanced thermal robustness and spectral tunability, and the development of wavelength-specific DFB arrays and structurally integrated on-chip sources for compact, multichannel sensing. Building on these device-level innovations, we also review representative III-V-on-chip sensing systems that integrate DFB lasers with modulators, waveguides, and detectors on silicon or SiN platforms. These systems enable diverse applications in multi-gas spectroscopy, LIDAR, biochemical analysis, and quantum communication. Finally, we discuss the opportunities and challenges in achieving compact, low-power, and multifunctional sensing platforms through advanced integration and photonic system design.