N-Bit, Lossless Variable Photonic Time Delay Module
This N-bit (N ≥ 10) Photonic Time Delay Module selectively routes optical signals through N fiber segments with the different lengths. Each fiber segment is defined to have the delay as
Where dT is the increment of time delay.
Therefore, the module provides N-bit of digitally variable time delay, having the total time delay as
N and dT can be defined by customer.
The EDFAs is used in the module to compensate the optical loss through optic fiber segments and switches. The optical loss between the optic fiber segment and the bypassing path is balanced internally to get the excellent uniformity of optical power between different time delays in long time delay ranges.