In a method of amplifying optical input signals over a wide bandwidth, the
optical input signals are applied to an optical waveguide made from a
rare-earth-doped amorphous material (e.g., erbium-doped yttrium aluminum
oxide material). The optical input signals include optical signals having
wavelengths over a range of at least 80 nanometers, and, preferably, over
a range of at least 160 nanometers. Pump light is applied to the optical
waveguide to cause the waveguide to provide optical gain to the optical
input signals. The optical gain causes the optical signals to be amplified
within the waveguide to provide amplified optical signals over the
extended 80-160-nanometer range, including, in particular, optical signals
having wavelengths at one end of the range and optical signals having
wavelengths at a second end or the range.
