Optical coherence tomography (OCT) system having integrated detector and analysis systems
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 system, comprising:
a hermetic package;
an optical bench installed within the hermetic package;
a swept source installed on the optical bench within the hermetic package and configured to generate a tunable source optical signal;
an interferometer splitter installed on the bench within the hermetic package and configured to split the source optical signal between a sample arm and a reference arm; and
an optical detector system comprising:
a first pair of optical detectors installed on the bench within the hermetic package for detecting a first polarization from the sample;
a second pair of optical detectors installed on the bench within the hermetic package for detecting a second polarization from the sample;
a first interference splitter/combiner installed on the bench within the hermetic package for generating interference signals of the first polarization from the source optical signal returning from the sample and the source optical signal returning from the reference arm, the interference signals to be detected by the first pair of optical detectors;
a second interference splitter/combiner installed on the bench within the hermetic package for generating interference signals of the second polarization from the source optical signal returning from the sample and the source optical signal from the reference arm, the interference signals to be detected by the second pair of optical detectors; and
an electronic amplifier system installed on the optical bench within the hermetic package, the electronic amplifier system comprises a first electronic amplifier for amplifying the output of the first pair of the optical detectors and a second electronic amplifier for amplifying the output of the second pair of the optical detectors.
2. A system as claimed in claim 1 , further comprising:
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 the first interference splitter/combiner; and
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 the second interference splitter/combiner.
3. A system as claimed in claim 1 , 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 interference splitter/combiner.
4. A system as claimed in claim 3 , 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 interference splitter/combiner.
5. A system as claimed in claim 1 , further comprising a reflective block, installed on the optical bench within the hermetic package, in the reference arm that receives and repeatedly reflects the source optical signal.
6. A system as claimed in claim 1 , further comprising:
a spectral filter, installed on the optical bench within the hermetic package, for filtering the source optical signal; and
a k-clock detector, installed on the optical bench within the hermetic package, 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.
7. An optical coherence analysis system, comprising:
an optical bench;
a first pair of the optical detectors installed on the bench for detecting a first polarization from a sample;
a second pair of the optical detectors installed on the bench for detecting a second polarization from the sample;
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 of the first polarization 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; and
a second detector interference splitter/combiner installed on the bench for generating interference signals of the second polarization 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.
8. A system as claimed in claim 7 , further comprising:
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; and
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.
9. A system as claimed in claim 7 , 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.
10. A system as claimed in claim 9 , 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.
11. A system as claimed in claim 7 , further comprising a reflective block, installed on the optical bench, in the reference arm that receives and repeatedly reflects the source optical signal.
12. A system as claimed in claim 7 , further comprising a swept source, installed on the optical bench, for generating the source optical signal.
13. A system as claimed in claim 7 , 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.
14. An optical coherence analysis method, comprising:
splitting a source optical signal from a source between a sample arm and a reference arm with an interferometer splitter installed on an optical bench;
transmitting a sample arm optical signal to a sample;
receiving a returning sample arm optical signal from the sample onto the optical bench;
combining the returning sample arm optical signal with a reference arm optical signal and splitting first polarization interference signals between a first pair of optical detectors on the bench; and
combining the returning sample arm optical signal with the reference arm optical signal and splitting second polarization interference signals between a second pair of optical detectors on the bench.