We have fabricated fibers with an a few nm thick Cd3P2 semiconductor layer at the clear glass core glass cladding boundary. We have measured a gain of approximately 7.1 dB in a 4 mm long piece of this Semiconductor Cylinder Fiber (SCF) at a wavelength of 1550 nm. The fiber section was pumped from the side with a 38 mW laser operating at a wavelength of 980 nm. We have reason to believe that the test wavelength of 1550 nm is near the short wavelength end of about a few hundred nm wide gain curve. The SCFs have applications as broad band Fiber Light Amplifiers.