Patent ID: 7724994

Claim:
An optical time delay module comprising: a. a plurality of rows of time delay elements connected in a series, an initial time delay element in an initial row in said series being responsive to an optical input to said module; b. a plurality of optical output couplers wherein each of said optical output couplers is operationally connected between each row of time delay elements in said series, the optical output couplers providing a plurality of optical outputs from said module with different optical delays controlled by a digital control word; c. wherein each row of time delay elements has a plurality of time delay elements coupled in series via optical switches, each time delay element having an associated optical bypass arranged so that an optical switch connected immediately upstream of one of the time delay elements and its associated optical bypass controls whether light passing via the switch is conveyed via said one of the time delay elements or its associated optical bypass; d. the optical switches being controlled to switch an output thereof onto either a following time delay element or following bypass by a bit of said digital control word.