On‐Chip Broadband Multiwavelength Microlaser Array in Visible Region

Abstract On‐chip integrated microlaser sources are critical components in silicon (Si) photonics, which has become one of the leading photonic integrated circuits (PICs) technologies due to low cost, eco‐friendly, large‐scale integration and inherent compatibility for complementary metal‐oxide‐semiconductor (CMOS) manufacturing processes. Until now, however, it still remains a significant challenge to achieve an active microlaser with a quality factor of up to 10 4 and heterogeneous integration of multiple broadband wavelength‐tunable microlasers for Si‐based PICs. Here, a scalable strategy is reported to realize simultaneous integration of multiwavelength GaN‐based microdisk laser arrays on Si(100) substrates. The microlaser exhibits a high‐quality factor of 13 138 and a low threshold density of 57.85 µJ cm −2 . By precisely modulating the microdisk size and/or shape and thus the corresponding cavity loss, the lasing wavelength can be dynamically tuned over a large spectral range from 455 to 503 nm, which is physically unraveled by the gain profile shifting for different threshold energy levels conditions. This study opens a new path toward the realization of on‐chip integrated broadband multiwavelength laser sources for Si‐PICs platform, where only an epi‐wafer and a single round of wafer bonding processes are needed.