Optical components and sub-systems for fiber optic networks and systems, namely, non-microphonic, low-phase noise source lasers, and tunable DFB (distributed feedback) lasers for various applications, namely, structural imaging, structural, monitoring, metropolitan and long haul DWDM (dense wavelength division multiplexing) networks, test and measurement systems, DWDM/EDFA (dense wavelength division multiplexing/erbium-doped fiber amplifier), interferometric interrogation systems, and systems...