Abstract: Provided is a signal detector and method for spectrum analysis and for measuring power of one or more channels of an electrical or optical signal. Each channel may carry a unique modulation tone. A DSP (digital-signal processor) performs DFTs (discrete Fourier transforms) on the signal. Frequency bands of interest which contain a tone that requires detection are processed. Higher layers of coherent integrations are performed on bands which have not detected a tone with a resolution that is suitable for power measurement. The higher layers of coherent integrations are performed by collecting additional data and performing a coherent integration. Further higher layer coherent integrations are performed until all modulation tones have been detected with a suitable resolution or up to a maximum detection latency.

Abstract: Channels in an optical WDM network are each identified by at least two dither tones with which the channel is modulated, the dither tones alternating with a predetermined periodicity so that at any instant each channel is modulated by only one dither tone. The dither tones are continuously generated at precise frequencies. Channel detection by detecting the dither tones, for channels having optical powers over a wide dynamic range, makes use of an FFT process which can detect dither tones for high power channels in a single operation. Coherent averaging of FFT results over time is used to detect dither tones for low power channels over multiple FFT operations.

Abstract: Channels in an optical WDM network are each identified by at least two dither tones with which the channel is modulated, the dither tones alternating with a predetermined periodicity so that at any instant each channel is modulated by only one dither tone. The dither tones are continuously generated at precise frequencies. Channel detection by detecting the dither tones, for channels having optical powers over a wide dynamic range, makes use of an FFT process which can detect dither tones for high power channels in a single operation. Coherent averaging of FFT results over time is used to detect dither tones for low power channels over multiple FFT operations.

Abstract: Channels in an optical WDM network are each identified by at least two dither tones with which the channel is modulated, the dither tones alternating with a predetermined periodicity so that at any instant each channel is modulated by only one dither tone. The dither tones are continuously generated at precise frequencies. Channel detection by detecting the dither tones, for channels having optical powers over a wide dynamic range, makes use of an FFT process which can detect dither tones for high power channels in a single operation. Coherent averaging of FFT results over time is used to detect dither tones for low power channels over multiple FFT operations.

Abstract: Methods and devices are provided for optical demultiplexing and optical multiplexing. An optical wavelength demultiplexer adapted to perform wavelength demultiplexing of an input optical signal containing a plurality of wavelengths is provided. A tuneable filter in combination with a device with a required free spectral range results in a tuneable demultiplexer arrangement which eliminates the need to inventory large numbers of different demultiplexers. Similarly, tuneable lasers in combination with a device with a required free spectral range result in a tuneable multiplexer arrangement.

Abstract: Methods and devices are provided for optical demultiplexing and optical multiplexing. An optical wavelength demultiplexer adapted to perform wavelength demultiplexing of an input optical signal containing a plurality of wavelengths is provided. A tuneable filter in combination with a device with a required free spectral range results in a tuneable demultiplexer arrangement which eliminates the need to inventory large numbers of different demultiplexers. Similarly, tuneable lasers in combination with a device with a required free spectral range result in a tuneable multiplexer arrangement.