PHASE OPTIMIZATION METHOD FOR TUNABLE OPTICAL DISPERSION COMPENSATOR, PHASE-OPTIMIZED TUNABLE OPTICAL DISPERSION COMPENSATOR, AND PHASE OPTIMIZATION DEVICE

摘要

PROBLEM TO BE SOLVED: To solve the problem in which: an unignorable deviation from a set value occurs in a dispersion value actually given by a LCOS (Liquid Crystal on silicon), even when the same voltage is applied, phase values actually set by pixels are slightly different in pixel numbers and there is position dependence on an x axis of the LCOS, and even when lookup table voltage data for one dispersion value is used to set an appropriate phase value at a certain pixel number, a value at another pixel number is deviated from the appropriate phase set value.;SOLUTION: A method of the present invention determines a difference between a phase set value obtained from a set target dispersion value and an actual output phase value of a LCOS obtained by integrating group delay spectrums associated with frequencies. Feedback is performed on a pixel applied voltage by regarding a value, to which a difference determined for a set target phase set value is added, as a new phase set value. An actually output phase distribution is closer to a set phase distribution of a quadratic function so that a group delay ripple is reduced. A pixel range for performing the feedback of a phase error is limited to a small range and convergence of the feedback is conducted at high speed.;COPYRIGHT: (C)2013,JPO&INPIT