Experimental integrated optic circuit losses, including waveguide bend, waveguide offsets, metal electrodes, and fiber-to-channel coupling, are presented. Coupling measurements from single-mode fibers to straight waveguides show losses less than 1 dB. Integrated optic circuit losses due to waveguide bends and offsets were calculated and measured; these data are in excellent agreement. A four-section

reversal switch has been permanently coupled to single-mode fiber pigtails with coupling losses approaching the measured optimum and theoretically predicted value.