Optical time-division multiplexing
AssigneeAlcatel
InventorAlbrecht Mozer
Life of this patent
Estimating the term…
Abstract
Optical time-division multiplexing of two or more digital optical input signals applied to an optical multiplex element to produce a single optical output signal is performed. In the multiplex element, the input signals are optically switched through in alternation, a through-switching time interval being shorter than the duration of a pulse of the input signal. An optical time-division multiplexer has at least one multiplex element to which at least two optical signal are input, the signals having carriers of different wavelengths. The signals are connected to an optical signal output via a junction. The signals can be switched through to the signal output in alternation by a switchable filter.
Claims18
A time-division optical multiplexer system, having a plurality of multiplexer elements the optical multiplexer elements comprising:
- a first optical waveguide for receiving and transmitting a first optical signal having a first optical carrier wavelength;
- a second optical waveguide for receiving and transmitting a second optical signal having a second optical carrier wavelength;
- and
- a third optical waveguide for alternately receiving the first and second optical signals and providing an optical output signal;
- said first and second optical waveguides being joined together at a junction;
- said third optical waveguide being coupled to said junction by switchable filter means for alternately passing one of the first and second optical signals;
- wherein:
- the plurality of multiplexer elements are arranged in a plurality of cascaded groups, each group having twice the elements of a following group;
- inputs of the elements in each respective group are connected to outputs of the elements in a respective preceding group;
- the switchable filter means of the elements of a respective group are controlled in synchronism by respective control signals;
- and
- the switchable filter means of the elements in each respective group are controlled by a control signal having a frequency twice the frequency of a following group.
An optical time-division multiplexer comprising:
- at least one multiplex element having inputs for receiving at least two optical signals, the signals having carriers of different wavelengths, the inputs being connected to an optical signal output via a junction, the element further having switchable filter means for switching the signals applied to the inputs to the signal output in alternation, wherein the multiplex element is controlled so that a switching time interval is shorter than a pulse duration of the input signals.
An optical multiplexer element comprising:
- a first optical waveguide for receiving and transmitting a first optical signal having a first optical carrier wavelength;
- a second optical waveguide for receiving and transmitting a second optical signal having a second optical carrier wavelength;
- and
- a third optical waveguide for alternately receiving the first and second optical signals and providing an optical output signal;
- and
- switchable filter means for alternately passing one of the first and second optical signals;
- wherein said first and second optical waveguides are joined together at a junction, and wherein said third optical waveguide is coupled to said junction by said switchable filter means for alternately passing one of the first and second optical signals, wherein the multiplexer element is controlled so that a switching time interval is shorter than a pulse duration of the first and second optical signals.
Dependencies are inferred from the claim text.