Abstract: A high-power single-frequency laser system and a method for implementing the same. The system and method require only a photodetector (110) and a narrow optical bandpass filter (108) to probe the spectral mode of slave laser (106), no additional bulky devices are required. The photodetector (110) and narrow optical bandpass filter (108) can be easily integrated into the beam path. The spectral mode of slave laser (106) is monitored through the reflected signal from the narrow-laser line filter (108), which is neither sensitive to beam alignment nor bandwidth limited. As a result, high spectral mode purity and low intensity noise of the slave laser (106) can be simultaneously obtained. The slave laser (106) can be locked even when the master laser (102) frequency is dynamically scanned over GHIz range. The system and method can be applied in laser cooling and trapping of atoms towards degenerate dipolar quantum gases.