The error of optical true time delay network caused by optical switches

To research the influence of optical switches on the optical true time delay network (OTTDN), the delay differences between the bar and cross states of a series of 2x2 optical switches are measured, and the results show that the average delay difference between the bar state and cross state is about 5.4ps. To verify this effect, a 2bit optical delay line based on 2x2 optical switches is constructed and measured. The time delay error is measured to be 5.34ps. Both analysis and experiment indicate that by replacing 2x2 optical switches with 1x2 optical switches, no error caused by optical switches remains.