Integrated OCT detector system with transimpedance amplifier
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 integrated optical detector system for use with an optical coherence analysis system, the integrated optical detector system comprising:
an optoelectronic package having two separate fiber feedthroughs for receiving two separate optical fibers therethrough, a first optical fiber configured to transmit a first incoming optical signal from a sample arm and a second optical fiber configured to transmit a second incoming optical signal from a reference arm of an interferometer of an optical coherence analysis system;
an optical bench installed within the optoelectronic package;
a balanced detector system installed on the optical bench, the balanced detector system including at least two optical detectors for receiving interference signals generated by a fiber optic combiner of the interferometer based on the first and second optical signals;
an electronic amplifier system installed on the optical bench within the optoelectronic package and in electrical communication with the at least two optical detectors, the electronic amplifier system including at least one electronic amplifier for amplifying an output of the at least two optical detectors; and
at least one lead extending from the optoelectronic package and in electrical communication with the at least one electronic amplifier, the at least one lead configured to provide an amplified output to an analog to digital converter system of the optical coherence analysis system for sampling of the amplified output, and the at least one lead further configured to provide power input to the at least one amplifier.
2. An integrated optical detector system as claimed in claim 1 , wherein the two separate fiber feedthroughs are positioned on opposing sides of the optoelectronic package.
3. An integrated optical detector system as claimed in claim 1 , wherein the balanced detector system comprises at least four optical detectors, and the integrated optical detector system comprises two polarization beam splitters installed on the optical bench that separate the interference signals into a first portion having a first polarization and a second portion having a second polarization and further transmit the first portion of interference signals to a first pair of the optical detectors and transmitting the second portion of interference signals to a second pair of the optical detectors.
4. An integrated optical detector system as claimed in claim 3 , wherein 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.
5. An integrated optical detector system as claimed in claim 1 , wherein the balanced detector system comprises at least four optical detectors, and the integrated optical detector system comprises two wavelength division beam splitters installed on the optical bench that transmit the interference signals within a first wavelength band to a first pair of the optical detectors and transmitting the interference signals within a second wavelength band to a second pair of the optical detectors.
6. An integrated optical detector system as claimed in claim 5 , wherein 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.
7. An integrated optical detector system as claimed in claim 1 , further comprising an ancillary detector installed on the optical bench that receives an ancillary optical signal from the interferometer.
8. An integrated optical detector system as claimed in claim 1 , wherein the ancillary detector is used to determine a spectral response of a sample.
9. An integrated optical detector system as claimed in claim 1 , further comprising a thermoelectric cooler installed on the optical bench an configured to stabilize a temperature of at least one of the balanced detector system and the electronic amplifier system.
10. An integrated optical detector system for use with an optical coherence analysis system, the integrated optical detector system comprising:
an optical bench installed within a hermetic optoelectronic package, the optoelectronic package having two separate fiber feedthroughs positioned on opposing sides of the optoelectronic package and for receiving separate associated optical fibers therethrough, the separate associated optical fibers configured to transmit incoming optical signals from a sample arm and a reference arm of an interferometer of an optical coherence analysis system external to the optoelectronic package;
at least one beam splitter/combiner installed on the bench that generates interference signals from a sample optical signal from the sample arm and a reference optical signal from the reference arm;
a balanced detector system installed on the optical bench, the balanced detector system including at least two optical detectors that receive the interference signals from the at least one beam splitter/combiner;
an electronic amplifier system installed on the optical bench for amplifying an output of the at least two optical detectors; and
a thermoelectric cooler installed on the optical bench an configured to stabilize a temperatures of at least one of the at least one beam splitter/combiner, the balanced detector system, and the electronic amplifier system.
11. An integrated optical detector system as claimed in claim 10 , wherein the balanced detector system comprises at least four of optical detectors, and the integrated optical detector system further comprises:
a first polarization beam splitter for dividing the interference signals into a first polarization and a second polarization;
a second polarization beam splitter for dividing the interference signals into a first polarization and a second polarization;
a first pair of the optical detectors that detect the interference signals of the first polarization; and
a second pair of the optical detectors that detect the interference signals of the second polarization.
12. An integrated optical detector system as claimed in claim 11 , wherein 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 is also included in the package.
13. An integrated optical detector system as claimed in claim 10 , further comprising at least one lead extending from the optoelectronic package and in electrical communication with the electronic amplifier system, the at least one lead configured to provide an amplified output to an analog to digital converter system of the optical coherence analysis system for sampling of the amplified output, and the at least one lead further configured to provide power input to the electronic amplifier system.
14. An optical coherence tomography system, comprising:
a hermetic optoelectronic package;
an optical bench installed within the optoelectronic package;
a swept source installed on the optical bench that generates a tunable optical signal;
an interferometer installed on the optical bench that transmits the tunable optical signal to a sample; and
an optical detector system, comprising:
first and second pairs of optical detectors installed on the optical bench;
at least two polarization beam splitters installed on the optical bench that transmit interference signals having a first polarization to the first pair of the optical detectors and transmitting the interference signals having a second polarization to the second pair of the optical detectors; and
an electronic amplifier system installed on the optical bench, 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.
15. An optical coherence tomography system as claimed in claim 14 , further comprising a thermoelectric cooler installed on the optical bench and configured to stabilize a temperature of at least one of the swept source, the interferometer, the first and second pairs of optical detectors, the two polarization beam splitters, and the electronic amplifier system.
16. An optical coherence tomography system, comprising:
a hermetic optoelectronic package;
an optical bench installed within the optoelectronic package;
a swept source installed on the optical bench that generates a tunable optical signal;
an interferometer installed on the optical bench that transmits the tunable optical signal to a sample;
an isolator installed on the optical bench that prevents back reflections from the interferometer from interfering with operation of the swept source; and
an optical detector system, comprising
a balanced detector system installed on the optical bench, the balanced detector system including at least two optical detectors that receive interference signals generated from the interferometer based, at least in part, on optical signals reflected from the sample; and
an electronic amplifier system installed on the optical bench for amplifying an output of the at least two optical detectors.
17. An optical coherence tomography system as claimed in claim 16 , wherein the balanced detector system comprises at least four optical detectors, and the optical detector system comprises two polarization beam splitters installed on the optical bench that transmit the interference signals having a first polarization to a first pair of the optical detectors and transmitting the interference signals having a second polarization to a second pair of the optical detectors.
18. An optical coherence tomography system as claimed in claim 17 , wherein 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.
19. An optical coherence tomography system as claimed in claim 16 , further comprising an ancillary detector installed on the optical bench that receives an ancillary optical signal.
20. An optical coherence tomography system as claimed in claim 19 , wherein the ancillary detector is used to determine a spectral response of the sample.
21. An optical coherence tomography system as claimed in claim 16 , further comprising:
at least one beam splitter/combiner installed on the optical bench that generates the interference signals from a sample optical signal from a sample arm and a reference optical signal from a reference arm of the interferometer.
22. An optical coherence tomography system as claimed in claim 16 , further comprising a thermoelectric cooler installed within the optoelectronic package for stabilizing a temperature of the balanced detector system and the electronic amplifier system.
23. An optical coherence tomography system as claimed in claim 16 , further comprising at least one lead extending from the optoelectronic package and in electrical communication with the electronic amplifier system, the at least one lead configured to provide the amplified output to an analog to digital converter system of the optical coherence analysis system for sampling of the amplified output, and the at least one lead further configured to provide power input to the electronic amplifier system.