Patent ID: 6751416
Filing Date: 2004-06-15
Classification: H04Q

Abstract:
A device, comprising:an input optical terminal to receive at least a portion of an optical carrier signal at a carrier wavelength that is modulated to carry data packets with headers having at least a first bit and a second bit, each data packet having a bit length in time that is not less than a pre-selected minimum bit length; an optical modulator having a first terminal to receive a first continuous-wave optical signal at a first wavelength and a second continuous-wave optical signal at a second wavelength, and a second terminal coupled to said input optical terminal to receive said portion of said optical carrier signal, said optical modulator configured to simultaneously modulate said first and said second continuous-wave optical signals in response to signal modulations in said optical carrier signal to output at said second terminal a first modulated signal at said first wavelength and a second modulated signal at said second wavelength, wherein said first and said second modulated signals carry said data packets and synchronize with each other in time; an optical delay unit coupled to receive said first and said second modulated signals and configured to produce a time delay between said first and said second modulated signals, wherein said time delay is substantially equal to said pre-selected minimum bit length to at least partially overlap said first bit of a header represented in one modulated signal with said second bit of said header represented in another modulated signal for each of said data packets; and a detection unit coupled to receive said first and said second modulated signals with said time delay from said optical delay unit and configured to determine whether values of said first and said second bits in said header of each data packet respectively match a selected first bit value and a selected second bit value.