An Optical Delay Line (ODL) is an electric-optic-electric instrument. It performs fixed time delay(s), between a few nanoseconds up to several hundred microseconds, for RF signals from 10MHz up to 40GHz and more. The RF input signal is converted into an optical modulated signal. The optical signal is transmitted into a long single mode fiber, usually at a 1.55 micron wavelength or similar. Passing the fiber, the optical signal is converted back into an electrical RF signal. The electrical control on the ODL elects the optical system automatically, with no need for tuning by the operator.