PM fiber beat length calculator
About this calculator
This calculator computes the polarization beat length of a polarization maintaining (PM) optical fiber. Beat length is the distance after which the polarization state has made one rotation, i.e. the phase shift between the two polarization modes is . Beat length is one way to define a PM fiber's birefringence, the other two being the index difference or the propagation constant difference between the polarization modes.
Either or (in ) can be given as input to the calculator along with the wavelength of the signal. is related to the index difference as follows
so the calculator first calculates (if necessary)