Integrated silicon photonics incorporates microelectronics and optoelectronics, a combination expected to revolutionize a variety of fields such as communication, sensing, lighting, displays, imaging and detection. Silicon lasers are the key to achieve integrated silicon photonics. However, the optical gains of silicon are lower than those of III-V compound semiconductors by one order of magnitude or two, due to its indirect bandgap feature. Although the fabrication of matured III-V compound lasers on silicon substrates has been proposed to circumvent this problem, the development of all-silicon laser is desired for integrated silicon photonics due to better compatibility with modern silicon techniques.