Optical system including optical devices having in-situ capacitive structures

An optical system, comprising:

• an optical modulator;
• a coupling waveguide disposed adjacent to the optical modulator and comprising a first capacitive structure formed along at least a portion of the coupling waveguide to detect light intensity inside the coupling waveguide;
• and
• a monitoring circuit electrically connected to the first capacitive structure at a first monitoring site and at a second monitoring site to cause generation of a first electrical signal and a second electrical signal via the first capacitive structure indicative of the light intensities at the first monitoring site and the second monitoring site, respectively, wherein the optical modulator is optically coupled to the coupling waveguide between the first monitoring site and the second monitoring site and the monitoring circuit determines an insertion loss of the optical modulator based on the first electrical signal and the second electrical signal.

A method, comprising:

• applying, by a monitoring circuit, reference variable voltage signals to a monitoring site of a first capacitive structure and a monitoring site of a second capacitive structure, wherein the first capacitive structure is formed in a coupling waveguide and the second capacitive structure is formed in an optical device optically coupled to the coupling waveguide;
• measuring, by the monitoring circuit, electrical signals generated at the monitoring site of the first capacitive structure and the monitoring site of the second capacitive structure;
• and
• determining, by the monitoring circuit, at least one of an amplification gain and an insertion loss caused by the optical device based on the measured electrical signals.