Disclosed herein is an optical fiber including a core doped with first
metal ions; and a cladding formed so as to surround the core and doped with second
metal ions selected so that the absorption coefficient in a transition wavelength
band of first transition of the first metal ions is greater than the absorption
coefficient in a transition wavelength band of second transition of the first metal
ions. The amplification of light due to the first transition is suppressed, and
at least the amplification or oscillation of light due to the second transition
is effected. Also disclosed are an optical amplification/oscillation device, a
laser light generating device, and a laser display unit, and a color laser display
unit each employing the optical fiber.
