Abstract: A fiber laser source is configured to an external reflective element disposed along the signal path of the fiber laser. The external reflective element comprises a wavelength-selective device that is designed to reflect all of the pump light that reaches the reflective element, while allowing the generated laser emission to pass through. The reflected pump light is then directed to pass through the fiber laser a second time to generating an additional amount of laser emission output. The external reflective element preferably comprises a fiber Bragg grating with a Bragg wavelength ?G that matches the pump wavelength ?P to provide essentially 100% reflection of any unabsorbed pump light.

Abstract: A high-power ASE source in the 2 ?m wavelength band is achieved by using a relatively high-power pump beam that is generated within a fiber laser-based pump source. An optical isolator is included along the pump output path and is critical in maximizing the level of output power in the generated ASE, since without its use the ASE source begins to exhibit self-lasing cavity modes at a relatively low power level. Various embodiments of the present invention are based upon the use of a two-stage (or more) arrangement for generating a high-power ASE output, including an ASE-generating stage for establishing the broadband ASE spectrum and an amplifier stage for increasing the optical power within the ASE spectrum. The amplifier stage itself may include one or more individual amplifying elements in a concatenated arrangement. Optical isolators are included along the signal paths to prevent the type of reflections that would otherwise trigger self lasing.

Abstract: A pulsed optical beacon source is formed of a fiber-based amplifier including a preamplifer stage (responsive to a CW seed laser source) and a booster stage coupled to the output of the preamplifier stage. The pump input to at least one stage is pulsed and controlled in a manner that allows for the formation of a pulsed beacon output that is able to perform the PAT requirements of a beacon source, while also allowing for a low bit rate (e.g., a few Hz to a few kHz) upstream data signal to be sent between the beacon source and a target's optical receiver.