Integrated dual swept source for OCT medical imaging
View Patent ↗An optical coherence analysis system comprising: a first swept source that generates a first optical signal that is tuned over a first spectral scan band, a second swept source that generates a second optical signal that is tuned over a second spectral scan band, a combiner for combining the first optical signal and the second optical signal to form a combined optical signal, an interferometer for dividing the combined optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample, and a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm.
1. An optical coherence analysis system comprising:
a first swept source that generates a first optical signal that is tuned over a first spectral scan band;
a second swept source that generates a second optical signal that is tuned over a second spectral scan band;
a combiner for combining the first optical signal and the second optical signal to form a combined optical signal;
an interferometer for dividing the combined optical signal between a reference arm and a sample arm leading to a sample, the interferometer including a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm, wherein the detector system comprises a first detector for detecting the interference signal resulting from the first optical signal and a second detector for detecting the interference signal resulting from the second optical signal; and
a polarization beam splitter for separating the interference signal into components resulting from the first optical signal and the second optical signal for detection by the first detector and the second detector.
2. An optical coherence analysis system as claimed in claim 1 , wherein each of the first swept source and the second swept source comprises:
a laser cavity having at least two reflectors, which define the longitudinal cavity modes;
a semiconductor gain medium in the laser cavity; and
a tuning element for the laser cavity.
3. An optical coherence analysis system as claimed in claim 2 , wherein the tuning element comprises a Fabry-Perot tunable filter.
4. An optical coherence analysis system as claimed in claim 2 , wherein the tuning element comprises an angled reflective Fabry-Perot tunable filter.
5. An optical coherence analysis system as claimed in claim 2 , wherein the tuning element comprises a MEMS Fabry-Perot tunable filter.
6. An optical coherence analysis system as claimed in claim 1 , wherein each of the first swept source and the second swept source comprises:
a broadband source for generating broadband light; and
a first tunable filter for spectrally filtering the broadband light from the broadband source to generate a tunable optical signal.
7. An optical coherence analysis system as claimed in claim 6 , wherein each of the first swept source and the second swept source further comprises:
an amplifier for amplifying the tunable optical signal to generate an amplified tunable optical signal; and
a second tunable filter for spectrally filtering the amplified tunable optical signal from the amplifier.
8. An optical coherence analysis system as claimed in claim 6 , wherein the first tunable filter comprises a Fabry-Perot tunable filter.
9. An optical coherence analysis system as claimed in claim 6 , wherein the first tunable filter comprises a MEMS Fabry-Perot tunable filter.
10. An optical coherence analysis system as claimed in claim 6 , wherein the broadband source is a superluminescent light emitting diode.
11. An optical coherence analysis system as claimed in claim 6 , wherein the broadband source is a semiconductor optical amplifier.
12. An optical coherence analysis system as claimed in claim 1 , further comprising:
a processing system for constructing an image from a response of the detector system.
13. An optical coherence analysis system as claimed in claim 1 , wherein the combiner comprises a WDM combiner.
14. An optical coherence analysis system as claimed in claim 1 , wherein the combiner comprises a polarization beam combiner.
15. An optical coherence analysis system as claimed in claim 1 , wherein the combiner comprises a beam switch.
16. An optical coherence analysis system as claimed in claim 1 , wherein the first optical signal and the second optical signal have orthogonal polarizations with respect to each other.
17. An optical coherence analysis system comprising:
a first swept source that generates a first optical signal that is tuned over a first spectral scan band;
a second swept source that generates a second optical signal that is tuned over a second spectral scan band;
a combiner for combining the first optical signal and the second optical signal to form a combined optical signal;
an interferometer for dividing the combined optical signal between a reference arm and a sample arm leading to a sample, the interferometer including a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm, wherein the detector system comprises a first detector for detecting the interference signal resulting from the first optical signal and a second detector for detecting the interference signal resulting from the second optical signal;
a tuning controller for controlling the tuning of the first optical signal over the first spectral scan band by the first swept source and the tuning of the second optical signal over the second spectral scan band by the second swept source; and
a polarization beam splitter for separating the interference signal for detection by the first detector and the second detector.