This series of ASE (Amplified Spontaneous Emission) light sources are single mode light source with a broad emission spectrum and relatively low-coherent. Our unit feature precision feedback control to provide high stability for accuracy measurement applications. The device is based on rare-earth-doped fibers with a pumping laser that is cooled for longevity. With the wide availability of doped fibers, we offer fiber optical light source with a wide range of wavelengths; including 540 nm, 850 nm, 1300 nm, 1480 nm, 1550nm, 1610nm, 1900nm, 2000nm, and 2400nm. They are the ideal light sources for FBG sensors, OCT, fiber optic gyroscopes, gas sensors, and fluorescence excitation, as well as for measurement of optical components. We produce both modular for system integration and stand-alone bench-top for ease in uses.