Integrated Lasers on Silicon at Communication Wavelength: A Progress Review

With the emerging trend of big data and internet of things, silicon (Si) photonics technology has been developed and applied for high-bandwidth data transmission. Contributed by the advantages of Si including high refractive index, low loss, significant thermal-optical effect, and CMOS compatibility, various functional photonic devices have been demonstrated. One exception is the laser source, which is limited by the indirect bandgap of Si. Researchers have come up with different ways to make lasers on Si. This review presents the development progress of integrated laser sources on Si, with the focus on the wavelength regimes for communication. These lasers are categorized based on their gain media, including III-V semiconductor-based laser, germanium/germanium tin-based laser, Raman-based laser, and rare-earth-doped laser. The laser performance and characteristics are summarized in tables for comparison. The key results are discussed. Future perspectives on the development of integrated lasers on Si have also been provided.