Patent ID: 7110674

Claim:
An optical add/drop device adapted to first and second optical paths, comprising: first and second optical add/drop units connected to said first and second optical paths, respectively; an add switch for selectively adding an optical signal to any one of said first and second optical add/drop units; and a drop switch for selectively dropping an optical signal from any one of said first and second optical add/drop units; each of said first and second optical add/drop units comprising: an optical demultiplexer for separating WDM signal light into n (n is an integer satisfying 1<n) optical signals having different wavelengths, said WDM signal light being obtained by wavelength division multiplexing said n optical signals; n optical switches each having first and second input ports and first and second output ports, said n optical signals output from said optical demultiplexer being supplied to said first input ports of said n optical switches, respectively; n regenerators connected to said first output ports of said n optical switches, respectively; and an optical multiplexer for wavelength division multiplexing optical signals output from said n regenerators; said add switch being connected to said second input ports of said n optical switches and adding said optical signal to one of said second input ports of said first and second optical add/drop unit; said drop switch being connected to said second output ports of said n optical switches and dropping said optical signal to one of said second output ports of said first and second optical add/drop units.