Thulium doped fiber amplifier pumping scheme

An optical amplifier comprising:

• a thulium-doped optical fiber comprising a first coil and a second coil;
• a first pump light emitting device optically coupled to said first coil for generating a first amplification pump wavelength;
• and
• a second pump light emitting device optically coupled to said second coil for generating a second amplification pump wavelength,
• wherein each of said first and second amplification pump wavelengths comprise at least one pre-selected wavelength to pump an excited state of the fiber,
• wherein said first amplification pump wavelength is a wavelength pre-selected to optimize the noise figure of said amplifier,
• wherein said second amplification pump wavelength is a wavelength pre-selected to optimize the optical efficiency of said amplifier, and
• wherein said first amplification pump wavelength has a shorter wavelength than said second amplification pump wavelength.

A method of amplifying an optical signal comprising the steps of:

• providing a thulium-doped optical fiber for transmitting an optical data signal;
• generating a first amplification pump wavelength corresponding to a first emission cross section of the 3H4 to 3F4 transition of the fiber;
• generating a second amplification pump wavelength corresponding to a second emission cross section of the 3H4 to 3F4 transition;
• and
• introducing said first amplification pump wavelength and said second amplification pump wavelength into said fiber, wherein the first pump wavelength corresponds to a lower emission cross section and lower excited state absorption cross section of the fiber than the second pump wavelength.