The 1.5 micron family narrow linewidth fiber laser is a continuous wave (CW) laser source in a highly reliable master-oscillator power-amplifier (MOPA) configuration with output power up to 5W. A particularly important field of application is in the area of sensors, e.g., fiber-optic sensors for strain and/or temperature measurements, various types interferometric sensing, trace gas detection with differential absorption LIDAR (DIAL), or wind speed measurements with Doppler LIDAR. This product is also useful for coherent detection schemes in the telecom. Also this laser can be used for wavelength conversion.