Optical phase change apparatus and method of changing a phase of an optical signal

A method of changing a phase of an optical signal, the method comprising:

• propagating the optical signal along an optical fiber link;
• coupling a first fiber portion of the optical fiber link to a first phase change device, the first phase change device configured for imparting a phase changing contribution to the first fiber portion via said coupling, the first phase change device operating within a first response frequency range;
• coupling a second fiber portion of the optical fiber link to a second phase change device, the second phase change device configured for imparting a phase changing contribution to the second fiber portion via said coupling, the second phase change device operating within a second response frequency range, the second response frequency range having a maximum response frequency value greater than a maximum response frequency value of the first response frequency range;
• and
• upon determining that said optical signal experiences a given phase change including a frequency greater than the first response frequency range:
• the first phase change device imparting, along the first fiber portion, a first phase change at a first response frequency value within the first response frequency range, and
• the second phase change device imparting, along the second fiber portion, a second phase change at a second response frequency value within the second response frequency range and greater than the first response frequency range, the first and second phase changes corresponding to the given phase change.

An optical apparatus comprising:

• an optical fiber link along which an optical signal propagates;
• a first phase change device coupled with a first fiber portion of the optical fiber link and configured for imparting a phase changing contribution to the first fiber portion via said coupling, the first phase change device operating within a first response frequency range;
• and a second phase change device coupled with a second fiber portion of the optical fiber link and configured for imparting a phase changing contribution to the second fiber portion via said coupling, the second phase change device operating within a second response frequency range, the second response frequency range having a maximum response frequency value greater than a maximum response frequency value of the first response frequency range, wherein, upon determining that said optical signal experiences a given phase change including a given frequency value greater than the first response frequency range:
• the first phase change device imparts, along the first fiber portion, a first phase change at a first response frequency within the first response frequency range;
• and the second phase change device imparts, along the second fiber portion, a second phase change at a second response frequency value within the second response frequency range and greater than the first response frequency range.