Electro-optical single-sideband modulator

摘要

An electro-optical single-sideband modulator comprising:
an electro-optical substrate;a bimodal optical waveguide structure formed in the substrate to support different optical modes having associated optical frequencies and optical propagation constants and comprising an optical input to receive an input optical carrier signal having an optical frequency, and a pair of optical outputs to output corresponding SSB modulated optical signals, each having an optical frequency spectrum with a single side lobe; and
an electrode structure formed on the substrate to receive an input electrical modulating signal having an associated electrical frequency and electrical propagation constant, and to responsively apply an electrical field to the bimodal optical waveguide structure.

主权项

1. An electro-optical single-sideband modulator (1) comprising:
an optical input (IN) to receive an input optical carrier signal having an optical frequency (ωS), and a pair of optical outputs (OUT1, OUT2) to output corresponding SSB modulated optical signals, each having an optical frequency spectrum with a single side lobe; an electro-optical substrate (2); a bimodal optical waveguide structure (3) formed in the substrate (2) to support different optical modes having associated optical frequencies (ωS, ωA) and optical propagation constants (βS, βA), and coupled between the optical input (IN) and the optical outputs (OUT1, OUT2) of the electro-optical single-sideband modulator (1) to receive the input optical carrier signal and responsively generate the SSB modulated optical signals; and an electrode structure (4) formed on the substrate (2) to receive an input electrical modulating signal having an associated electrical frequency (Ω) and electrical propagation constant (βΩ), and to responsively apply an electrical field to the bimodal optical waveguide structure (3); wherein the bimodal optical waveguide structure (3) and the electrode structure (4) are so formed that the optical propagation constants (βS, βA) of the optical modes and the electrical propagation constant (βΩ) of the electrical modulating signal meet a Phase Matching condition, according to which the optical propagation constant (βA) of a first one of the optical modes is equal to the sum of the optical propagation constant (βS) of a second one of the optical modes and the electrical propagation constant (βΩ) of the electrical modulating signal, so resulting in the energy of the first optical mode being transferred at least partially to the second optical mode, and, as a consequence, in the optical frequency (ωA) of the second optical mode being equal to the optical frequency (ωS) of the first optical mode up-shifted of the electrical frequency (Ω) of the electrical modulating signal, and the SSB modulated optical signals are outputted externally to the single-sideband modulator separately through the optical outputs (OUT1, OUT2) without interfering with one another.