Determination of fiber optic single mode bending losses has been computed by using Optifiber software with wavelength of 1310 nm, 1383 nm, 1550 nm, and bendin fiber from 2 mm-60 mm. The result shows that the largest loss of material at λ = 1383 nm is 0,843 dB/km, the ultraviolet absorption loss at λ = 1310 nm is 0,306 dB/km, the infrared absorption loss at λ = 1550 nm is 2,037 x 10-2 dB/…