LAUSR

The ever‐increasing demand for information density and accuracy in highly integrated photonic devices calls for miniaturization of a coherent light source with broadband tunability and high stability. Wavelength tuning range, cavity Q factor, and threshold are three indicators of evaluating the performance of a nanoscale laser. Herein, the latest, effective materials and fundamental structures for multicolor semiconductor lasers including low dimensional II–VI semiconductors, III–V semiconductors, and lead halide perovskites are reviewed. Composition and bandgaps, novel cavity designs, lasing wavelength, Q factors of resonators, and lasing thresholds of the multicolor semiconductor lasers are compared and discussed. Finally, a summary and a future perspective of broadband tunable semiconductor lasers are given.