Multi-channel interference (MCI) laser is a novel monolithically integrated widely-tunable semiconductor laser. It applies multi-arm interference based mode selection, and achieves wide tuning through either electro-optic effect or thermo-optic effect. It has the advantage of simple fabrication and large fabrication tolerance. The active and passive integration of the MCI laser utilizes the offset quantum well scheme, which reduces the difficulty for regrowth. The wavelength tuning range of the electrically tuned MCI laser is greater than 48nm, the output power is greater than 20mW, and the Lorentzian linewidth is less than 350kHz. The wavelength tuning range of thermally tuned MCI laser is greater than 60nm, and the Lorentzian linewidth over the entire tuning range is less than 100kHz at dual temperatures. Meanwhile, the research advances its stability control and integration, and demonstrates nano-ITLA based on thermally-tuned MCI lasers.