The 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 10 MHz up to 20 GHz and more (there are low-frequency ODL versions from 10 MHz to 5 GHz, and high-frequency ODLs versions up to 8 GHz, 15 GHz, 18 GHz and 20 GHz. 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.
An Optical Delay Lines system (ODL) incorporates high performance lasers such as DFBs, optical modulators for high operation frequencies, photodiodes, and optionally other components such as optical dispersion compensators, optical switches, optical amplifiers and pre- and post RF amplifiers to provide exceptionally high performance. The ODL optical system supports very high bandwidths of analog signals, high sensitivity with wide dynamic range, for various delays.