Methods and apparatus for sensing multiple wavelengths simultaneously in a single wavelength sensing device
View Patent ↗A method and system provide for sensing multiple wavelengths simultaneously in a single wavelength sensing device. The system may have a plurality of laser signals and a plurality of identifiable modulation signals. A respective laser signal of the plurality of laser signals is combined with a respective identifiable modulation signal of the plurality of identifiable modulation signals so that each of the laser signals is identifiable. A combined optical signal is then formed from the modulated laser signals. A sensor has an input port that receives the combined optical signal. The sensor identifies, for each of the modulated laser signals, a respective laser signal via the identifiable modulation of the respective modulated laser signal.
1. A method for sensing multiple wavelengths comprising:
providing a plurality of different substantially monochromatic optical signals, each signal having a respective wavelength;
providing a plurality of identifiable modulation signals;
modulating each member of the plurality of optical signals with a respective identifiable modulation signal from the plurality of identifiable modulation signals and forming a combined optical signal;
forming for each of the optical signals, respective first and second representations which are associated with a respective identifiable modulation signal of the plurality of identifiable modulation signals; and
forming a respective ratio from the first and second representations.
2. A method as in claim 1 including using the ratio to adjust the wavelength of a respective optical signal.
3. A method as in claim 2 which includes forming a plurality of ratios to adjust the wavelength of each of the optical signals.
4. A method as in claim 3 which includes providing at least one of circuitry, or software which forms the ratios.
5. A method of controlling a plurality of optical sources, comprising:
providing a plurality of optical sources, each of the sources emits an optical signal having a respective wavelength;
providing a plurality of identifiable modulation signals;
modulating a respective optical signal of the plurality of signals with a respective identifiable modulation signal of the plurality of identifiable modulation signals and forming a combined optical signal; and
forming a respective control signal, for each of the optical signals in the plurality by forming first and second electrical representations of each member of the plurality of identifiable modulation signals at a common element.
6. A method as in claim 5 where forming includes filtering first and second representations to isolate identifiable modulation signals.
7. A method as in claim 5 which includes activating each member of the plurality of identifiable modulation signals and filtering the first and second electrical representations.
8. A method as in claim 6 where the control signals each adjust a temperature parameter of a respective optical source.
9. A method as in claim 6 which includes digitizing the first and second representations prior to filtering them.
10. An optical communications system comprising:
a plurality of lasers, each of the lasers has at least
a non-traffic modulation input and a wavelength adjusting input, each member of the plurality emits an optical output;
a plurality of non-traffic modulation sources, each member of the plurality of sources is coupled to a non-traffic modulation input of a respective laser;
a combiner coupled to the optical outputs, the combiner forming a composite optical output;
a wavelength locker coupled to the composite optical output, the locker emitting first and second output signals;
at least first and second non-modulation source detectors associated with a selected modulation source and coupled to the first and second output signals; and
control circuitry, responsive to outputs from the detectors, that couples a control signal to a wavelength adjusting input of a laser associated with the selected modulation source.
11. A system as in claim 10 which includes a plurality of pairs of non-traffic modulation source detectors, each pair is associated with a respective non-traffic modulation source.
12. A system as in claim 11 where the control circuitry responds to respective pairs and couples a respective control signal to a wavelength adjusting input of a respective laser.
13. A system as in claim 10 where the non-modulation source detectors comprise a programmed processor.
14. A system as in claim 13 which includes at least first and second analogue-to-digital converters.
15. A system as in claim 14 which includes filtering software, executed by the processor.
16. A method comprising:
generating a plurality of modulatable, substantially mono-chromatic beams of radiant energy with each member of the plurality having a predetermined wavelength;
modulating each member of the plurality with respective identification signal;
forming a composite optical beam;
converting the beam into a plurality of electrical signals with respective pairs of electrical signals associated with a respective identification signal;
using respective pairs of electrical signals to adjust the wavelength of a respective member of the plurality of modulatable beams.
17. A method as in claim 16 where converting includes providing a wavelength locker to produce the plurality of pairs of electrical signals.
18. A method as in claim 17 which includes coupling first and second outputs from the wavelength locker to a plurality of pairs of filters where pairs of the filters are associated with respective identification signals.
19. A method as in claim 17 which includes forming a plurality of ratios of pairs of electrical signals.
20. A method as in claim 17 including using each pair of signals to adjust the wavelength of a respective modulatable beam.
21. A method as in claim 16 where converting includes digitizing and filtering the signals to form a plurality of wavelength control signals which are associated with respective modulatable beams of radiant energy.