Systems, methods, and media for multiple beam optical coherence tomography
Systems, methods, and media for multiple beam optical coherence tomography are provided which, in some embodiments, include: a light source; a splitter that outputs a fraction of light to various waveguides; optical components that receive light from the waveguides and direct the light as beams that simultaneously impinge a sample at different lateral positions, and collect backscattered light from the lateral positons; another splitter that outputs a fraction of light to waveguides of a reference arm as reference light samples; a mixer that receives the backscattered light samples and the reference light samples, and combines each backscattered sample with a corresponding reference sample such that the mixer outputs fringes; and a detector that receives the fringes, and outputs OCT signals, each indicative of a structure of the sample at a respective lateral position.
1. A system for multiple beam optical coherence tomography, comprising:
a sample arm optically configured to be coupled to a light source, the sample arm comprising:
a first optical fiber comprising a proximal end optically coupled to the light source and a distal end,
a first splitter optically coupled to the distal end of the first optical fiber and optically coupled to a proximal end of each of a first plurality of optical fibers, wherein the first plurality of optical fibers comprises n optical fibers, and
a first plurality of optical components configured to:
receive from the plurality of optical fibers a respective plurality of beams,
cause the plurality of beams to be emitted toward a sample,
receive a plurality of backscattered light samples from the sample,
wherein the plurality of backscattered light samples are spatially separated, and
wherein each of the plurality of backscattered light samples corresponds to one of the plurality of beams, and
direct the plurality of backscattered light samples toward a detector;
a reference arm optically coupled to the light source, the reference arm comprising:
a second optical fiber comprising a proximal end optically coupled to the light source and a distal end, and
a second splitter optically coupled to the distal end of the second optical fiber and optically coupled to a proximal end of each of a second plurality of optical fibers, wherein the second plurality of optical fibers comprises n optical fibers;
a second plurality of optical components configured to:
combine each of the plurality of backscattered light samples with a beam emitted by a corresponding optical fiber of the second plurality of optical fibers yielding a plurality of fringes, and
direct each of the plurality of fringes to a corresponding channel of the detector,
the second plurality of optical components comprising a beam splitter comprising a first port, a second port, and a third port,
the first port being configured to receive light emitted by the second plurality of optical components,
the second port being configured to receive the plurality of backscattered light samples, and
the third port being configured to output the plurality of fringes; and
the detector comprising a plurality of detection channels, the detector configured to output optical coherence tomography data indicative of a structure of the sample at a plurality of locations that generated the plurality of backscattered light samples,
the detector comprising a plurality of balanced detectors comprising a first port and a second port, each of the plurality of balanced detectors corresponding to a respective channel of the detector,
the beam splitter further comprising a fourth port configured to output a second plurality of fringes, and
each of the plurality of balanced detectors receiving a fringe of the plurality of fringes and a corresponding fringe of the second plurality of fringes and outputting a signal based on both fringes.
2. The system of claim 1 , wherein the light source is a wavelength-swept laser.
3. The system of claim 1 , wherein the light source is a wavelength-stepped frequency comb source.
4. The system of claim 1 , wherein the sample arm further comprises:
a first spatial separator mechanically coupled to a distal end of each optical fiber of the first plurality of optical fibers.
5. The system of claim 4 , wherein the first spatial separator comprises a V-groove assembly.
6. The system of claim 1 , wherein the reference arm further comprises:
a second spatial separator mechanically coupled to a distal end of each optical fiber of the second plurality of optical fibers.
7. The system of claim 1 , wherein the light source emits light in a spectral range centered on 1300 nanometers.
8. The system of claim 1 , wherein the first splitter comprises a planar lightwave circuit splitter that receives light from the first optical fiber and splits the received light into n outputs.
9. The system of claim 1 , wherein the first plurality of optical components comprises:
a first lens having a first side optically coupled to the first plurality of optical fibers and a second side, wherein the first lens is configured to focus the plurality of beams at a first focal distance corresponding to a focal length of the first lens;
a surface configured to redirect light received from the second side of the first lens toward a first side of a second lens and redirect light received from the first side of the second lens toward the second side of the first lens; and
the second lens having the first side optically coupled to the surface and a second side configured to direct light received from the surface toward the sample and receive the plurality of backscattered light samples from the sample.
10. The system of claim 9 , wherein the first plurality of optical components comprises:
a third lens having a first side optically coupled to the first plurality of optical fibers and a second side, wherein the third lens is configured to focus the plurality of beams at a first focal distance corresponding to a focal length of the third lens;
a polarizing beam splitter comprising a first port, a second port, and a third port and a first interface that passes light having a first polarization and redirects light having a second polarization,
wherein the beam splitter is configured to pass light having the first polarization received at the first port to the second port and redirect light having the second polarization received at the second port toward the third port,
wherein the first port is optically coupled to the second side of the third lens such that the first port receives the plurality of beams from the third lens,
wherein the second port is optically coupled to a first side of a fourth lens such that the second port emits the plurality of beams toward the fourth lens and receives the plurality of backscattered light samples from the fourth lens, and
wherein the third port is configured to emit the plurality of backscattered light samples toward a fifth lens;
the fourth lens having the first side optically coupled to the second port and having a second side;
a quarter wave plate optically coupled to the second side of the fourth lens and a first side of the first lens,
wherein the first side of the first lens is optically coupled to the quarter wave plate; and
the fifth lens having a first side optically coupled to the third port of the polarizing beam splitter and a second side optically coupled to a third plurality of optical fibers,
wherein the first plurality of optical fibers and the third plurality of optical fibers are oriented such that light emitted from the first plurality of optical fibers is transmitted to respective optical fibers of the third plurality of optical fibers.
11. The system of claim 10 , further comprising a spatial separator mechanically coupled to a distal end of each optical fiber of the third plurality of optical fibers, and disposed to optically couple each optical fiber of the third plurality of optical fibers to the first side of the first lens.
12. The system of claim 1 , wherein the first plurality of optical components comprises:
a plurality of optical circulators, each of the optical circulators having a first port, a second port, and a third port,
wherein the first port of each of the plurality of optical circulators is optically coupled to the light source via a respective optical fiber of the first plurality of optical fibers,
the second port of each of the plurality of optical circulators is optically coupled to the sample via a respective optical fiber of a third plurality of optical fibers, and
the third port of each of the plurality of optical circulators is optically coupled to the second plurality of optical components via a respective optical fiber of a fourth plurality of optical fibers.
13. The system of claim 1 , wherein the first plurality of optical components comprises:
a second planar lightwave circuit comprising a plurality of optical couplers, each having a first port, a second port, and a third port,
wherein the first port of each of the plurality of optical couplers is optically coupled to the light source via a respective optical fiber of the first plurality of optical fibers,
the second port of each of the plurality of optical couplers is optically coupled to the sample via a respective optical fiber of a third plurality of optical fibers, and
the third port of each of the plurality of optical couplers is optically coupled to the second plurality of optical components via a respective optical fiber of a fourth plurality of optical fibers.
14. The system of claim 13 , wherein each of the plurality of optical couplers is configured to:
output, from the third port, a first fraction of light received at the first port;
output, from a fourth port, a second fraction of light received at the first port;
output, from the first port, the first fraction of light received at the third port; and
output, from the second port, the second fraction of light received at the third port.
15. The system of claim 14 , wherein a ratio between the first fraction and the second fraction is approximately equal to one.
16. The system of claim 14 , wherein a ratio between the first fraction and the second fraction is less than one.
17. The system of claim 1 , wherein the reference arm further comprises a modulation component disposed between the light source and the second splitter, the modulation component configured to modulate at least polarization of light provided to the second splitter.
18. The system of claim 17 , wherein the modulation component comprises:
a coupler comprising:
a first port optically coupled to the light source;
a second port; and
a third port;
a first phase modulator comprising:
a first port optically coupled to the second port of the coupler; and
a second port;
a second phase modulator comprising:
a first port optically coupled to the third port of the coupler; and
a second port; and
a beam combiner comprising:
a first port optically coupled to the first phase modulator;
a second port optically coupled to the second phase modulator; and
a third port.
19. The system of claim 18 , wherein the modulation component further comprises:
a polarization controller optically coupled to the second port of the coupler and the first port of the first phase modulator.
20. The system of claim 18 , wherein the modulation component further comprises:
a polarization controller optically coupled to the third port of the coupler and the second port of the second phase modulator.
21. The system of claim 1 , wherein the second plurality of optical components comprises:
a plurality of optical couplers, each having a first port, a second port, a third port, and a fourth port,
wherein the first port is coupled to the light source via a respective optical fiber of the second plurality of optical fibers;
the second port is coupled to the sample via a respective optical fiber of a plurality fourth plurality of optical fibers;
the third port is coupled to a respective channel of the plurality of detection channels; and
the fourth port is coupled to the respective channel of the plurality of detection channels.
22. The system of claim 21 , further comprising a third planar lightwave circuit, wherein the third planar lightwave circuit comprises the plurality of optical couplers.
23. The system of claim 1 , wherein the reference arm further comprises a modulation component disposed between the light source and the second splitter, the modulation component configured to modulate at least a phase of light provided to the second splitter.
24. The system of claim 1 , wherein the sample arm further comprises a modulation component disposed between the light source and the first splitter, the modulation component configured to modulate at least a phase of light provided to the first splitter.
25. The system of claim 1 , wherein the sample arm further comprises a modulation component disposed between the light source and the first splitter, the modulation component configured to modulate at least polarization of light provided to the first splitter.
26. A system for multiple beam optical coherence tomography, comprising:
a first splitter arranged to receive first light from a light source and output a fraction of the first light to each of a first plurality of waveguides;
optical components arranged to:
receive light from the first plurality of waveguides;
direct the received light as a plurality of beams toward a sample such that each of the plurality of beams impinges the sample at a different lateral position; and
collect a plurality of backscattered light samples from the different lateral positions of the sample;
a second splitter arranged to receive second light from the light source and output a fraction of the second light to each of a second plurality of waveguides as a plurality of reference light samples;
a mixer arranged to receive the plurality of backscattered light samples and the plurality of reference light samples and combine each backscattered light sample with a corresponding reference light sample such that the mixer outputs a plurality of fringes,
the first splitter comprising a planar lightwave circuit splitter comprising a plurality of optical couplers, each having a first port, a second port, and a third port,
the first port of each of the plurality of optical couplers being optically coupled to the light source,
the second port of each of the plurality of optical couplers being optically coupled to the sample, and
the third port of each of the plurality of optical couplers being optically coupled to the mixer; and
a detector arranged to receive the plurality of fringes and output a plurality of optical coherence tomography signals,
each of the plurality of optical coherence tomography signals being indicative of a structure of the sample at a respective lateral position.
27. The system of claim 26 , wherein the plurality of beams comprises eight beams.
28. The system of claim 26 , wherein the optical components comprise:
a plurality of optical circulators, each of the plurality of optical circulators arranged to:
receive a beam of the plurality of beams from a waveguide of the first plurality of waveguides;
direct the received beam toward the sample; and
direct a backscattered light sample toward the detector.
29. The system of claim 26 , wherein the optical components comprise:
a plurality of optical couplers, each of the plurality of optical couplers arranged to:
receive a beam of the plurality of beams from a waveguide of the first plurality of waveguides;
direct the received beam toward the sample; and
direct a backscattered light sample toward the detector.