Integrated optical coherence tomography system
View Patent ↗An optical detector system comprises a hermetic optoelectronic package, an optical bench installed within the optoelectronic package, a balanced detector system installed on the optical bench. The balanced detector system includes at least two optical detectors that receive interference signals. An electronic amplifier system installed within the optoelectronic package amplifies an output of at least two optical detectors. Also disclosed is an integrated optical coherence tomography system. Embodiments are provided in which the amplifiers, typically transimpedance amplifiers, are closely integrated with the optical detectors that detect the interference signals from the interferometer. Further embodiments are provided in which the interferometer but also preferably its detectors are integrated together on a common optical bench. Systems that have little or no optical fiber can thus be implemented.
1. An optical coherence analysis system, comprising:
an interferometer splitter for splitting a source optical signal from a source between a sample arm and a reference arm;
a first sample arm polarization beam splitter through which the source optical signal is transmitted to a sample, the first sample arm polarization beam splitter directing a first polarization of the source optical signal returning from the sample to a first pair of the optical detectors;
a second sample arm polarization beam splitter through which the source optical signal is transmitted to the sample, the second sample arm polarization beam splitter directing a second polarization of the source optical signal returning from the sample to a second pair of the optical detectors; and
a non-reciprocal sample polarization rotation system between the first sample arm polarization beam splitter and the second sample arm polarization beam splitter.
2. A system as claimed in claim 1 , further comprising a first reference arm beam splitter through which the source optical signal is transmitted in the reference arm, the first reference arm beam splitter directing the source optical signal in the reference arm to the first pair of the optical detectors.
3. A system as claimed in claim 2 , further comprising a second reference arm beam splitter through which the source optical signal is transmitted in the reference arm, the second reference arm beam splitter directing the source optical signal in the reference arm to the second pair of the optical detectors.
4. A system as claimed in claim 1 , further comprising a first detector interference splitter/combiner for generating interference signals detected by the first pair of detectors from the first polarization of the source optical signal returning from the sample and the source optical signal from the reference arm.
5. A system as claimed in claim 4 , further comprising a second detector interference splitter/combiner for generating interference signals detected by the second pair of detectors from the second polarization of the source optical signal returning from the sample and the source optical signal from the reference arm.
6. A system as claimed in claim 1 , further comprising a reference arm non-reciprocal reference polarization rotation system between the first reference arm beam splitter and the second reference arm beam splitter and where the two reference arm beam splitters are polarization beam splitters.
7. A system as claimed in claim 1 , further comprising a reflective block in the reference arm that receives and repeatedly reflects the source optical signal.
8. A system as claimed in claim 1 , further comprising a swept source for generating the source optical signal.
9. A system as claimed in claim 8 , further comprising an isolator for preventing back reflections into the swept source.
10. A system as claimed in claim 1 , further comprising:
a spectral filter for filtering the source optical signal; and
a k-clock detector for detecting the spectrally filtered source optical signal to generate a k-clock signal for triggering sampling of the output of the first and second pairs of detectors.
11. A system as claimed in claim 1 , further comprising an optical bench, the first sample arm polarization beam splitter, the second sample arm polarization beam splitter, first pair of the optical detectors, and the second pair of optical detectors, being installed together on the optical bench.
12. A system as claimed in claim 11 , wherein the optical bench is installed within a hermetic package.
13. An optical coherence analysis system, comprising:
an optical bench;
a first pair of the optical detectors installed on the bench;
a second pair of the optical detectors installed on the bench;
an interferometer splitter installed on the bench for splitting a source optical signal from a source between a sample arm and a reference arm;
a first detector interference splitter/combiner installed on the bench for generating interference signals detected by the first pair of optical detectors from the source optical signal returning from a sample and the source optical signal from the reference arm;
a second detector interference splitter/combiner installed on the bench for generating interference signals detected by the second pair of optical detectors from the source optical signal returning from the sample and the source optical signal from the reference arm;
a first sample arm beam splitter through which the source optical signal is transmitted to the sample, the first sample arm beam splitter directing the source optical signal returning from the sample to first detector interference splitter/combiner;
a second sample arm beam splitter through which the source optical signal is transmitted to the sample, the second sample arm beam splitter directing the source optical signal returning from the sample to second detector interference splitter/combiner; and
a non-reciprocal sample polarization rotation system between the first sample arm beam splitter and the second sample arm beam splitter.
14. A system as claimed in claim 13 , further comprising a first reference arm beam splitter through which the source optical signal is transmitted, the first reference arm beam splitter directing the source optical signal from the reference arm to the first detector interference splitter/combiner.
15. A system as claimed in claim 14 , further comprising a second reference arm beam splitter through which the source optical signal is transmitted, the second reference arm beam splitter directing the source optical signal from the reference arm to the second detector interference splitter/combiner.
16. A system as claimed in claim 13 , further comprising a reflective block, installed on the optical bench, in the reference arm that receives and repeatedly reflects the source optical signal.
17. A system as claimed in claim 13 , further comprising a swept source, installed on the optical bench, for generating the source optical signal.
18. A system as claimed in claim 13 , further comprising:
a spectral filter, installed on the optical bench, for filtering the source optical signal; and
a k-clock detector, installed on the optical bench, for detecting the spectrally filtered source optical signal to generate a k-clock signal for triggering sampling of the output of the first and second pairs of detectors.