Depolariser based on acousto-optical TE-TM converters for suppression of polarisation holeburning in long haul EDFA links

A depolarized Er-doped superfluorescent fibre source with a 3-section Lyot fibre depolarizer

“…There are many methods that have been developed to produce depolarized light in an optical fibre context [5][6][7]; the most common method is the use of the fibre Lyot depolarizer. This method works by causing the polarization state to vary rapidly with wavelength.…”

Polarization mode dispersion detected by arrival time measurement of polarization-scrambled light

“…It can be constructed from and plates rotating at different speeds, or the electro-(or acoustooptical) analogons thereof [9]- [11]. Concatenation [10] can overcome even severe shortcomings of individual nonideal scramblers. An ideal scrambler will make mean and root mean square (rms) value of each normalized Stokes parameter at its output equal to 0 and , respectively, and the normalized Stokes parameters will be uncorrelated.…”

“…The VCO slope (e.g., Hz/V) is . The clock recovery PLL is governed by (8) Usually, a proportional-integral controller is chosen This results in transfer functions with (10) The clock phase noise caused by the received clock phase has the variance (11) The power spectral density of the white spectrum of the received phase noise can be measured after the phase detector to determine , using the transmitter clock signal and no PLL. The variance of the clock phase noise caused by white Gaussian frequency noise is (12) Here, if the clock signal has a Lorentzian line with a width .…”