Broadband tm-doped optical fiber amplifier

An optical system for providing amplified spontaneous emission in an eye-safe wavelength band, comprising:

• a section of single-clad optical gain fiber, including a Tm-doped core region;
• and
• a pump source including a laser diode source and a fiber laser coupled to the laser diode source, the fiber laser creating pump light at a defined pump wavelength λP2 with an output power in the range of 1-3 W, the pump light coupled into the Tm-doped core region of the single-clad optical gain fiber so as to interact with Tm ions, generating as an output amplified spontaneous emission centered at a wavelength within the eye-safe wavelength band.
• input signal and create an increase in optical power of the propagating input signal as it exits the single-clad optical gain fiber.

A multi-stage optical amplifier for operation at an eye-safe input signal wavelength λS within the 2 μm region, comprising:

• a plurality of N sections of single-clad Tm-doped optical fiber disposed in a concatenated configuration, each section defining a separate stage of the multi-stage optical amplifier, wherein an input signal is coupled into a first, input stage of the multi-stage optical amplifier;
• a pump source providing pump light at a defined pump wavelength λP with a multi-watt output power, the pump source including a laser diode source and a fiber laser coupled to the laser diode source, wherein defined parameters of the fiber laser are configured to provide a multi-watt output at the defined pump wavelength λP2;
• and
• a 1:N power splitter coupled between an output of the pump source and a pump light input of each stage of the multi-stage amplifier so as to provide a separate pump beam for propagating through each section of single-clad Tm-doped optical fiber of the plurality of N sections of single-clad Tm-doped optical fiber, each pump beam interacting with the propagating input signal and creating an increase in optical power of the propagating input signal as it passes through each stage of the multi-stage optical amplifier.