Patent ID: 8068746

Claim:
A method for balancing optical transmission for a first ON state and a second ON state to find a minimum off state of an electro-optic switch having an RF input port and a DC port, the method comprising the steps of: (a) associating a positive RF voltage with the first ON state of the electro-optic switch; (b) associating a negative RF voltage with the second ON state of the electro-optic switch, wherein absolute value of the negative RF voltage associated with the second ON state is approximately equal to the positive RF voltage associated with the first ON state; (c) balancing optical transmission of the first ON state and the second ON state by adjusting a voltage applied to the DC port to obtain minimum optical transmission in an OFF state of the electro-optic switch; (d) selecting an initial DC voltage level and an initial RF port voltage by measuring visibility over a range of predetermined DC voltages and a range of predetermined RF port voltages, then selecting the initial DC voltage associated with minimum measured visibility; (e) determining visibility slope as a function of DC voltage; and (f) applying a correction voltage to the initial DC voltage level, where the correction voltage is a function of visibility measured at operating values of DC port voltage and RF port voltage, and the visibility slope.