Mode-Evolution Compound Converter

A mode-evolution compound converter for converting an optical signal including a first component having a fundamental transverse magnetic (TM) mode and a second component having a fundamental transverse electric (TE) mode, comprising:

• a polarization converter for converting the fundamental TM mode of the first component into a second order TE mode;
• and
• a spatial converter for converting the second order TE mode of the first component into the fundamental TE mode and for splitting the first and the second components of the optical signal into a first TE mode signal and a second TE mode signal.

A mode-evolution compound converter for processing an optical signal, wherein the optical signal includes a component having a fundamental transverse magnetic (TM) mode, comprising:

• a set of multiple converters connected to form a compound converter, wherein each converter is a mode-evolution converter selected from a group including a polarization converter, a spatial converter, a reverse polarization converter, a reverse spatial converter, a high-order mode filter and combination thereof, wherein the polarization converter and the reverse polarization converter at least converts a mode of a polarization of at least one component of the optical signal, and the spatial mode converter and the reverse spatial mode converter at least converts a spatial mode order of at least one component of the optical signal.