OCT Combining Probes and Integrated Systems
Optical coherence tomography (OCT) probe and system designs are disclosed that minimize the effects of mechanical movement and strain to the probe to the OCT analysis. It also concerns optical designs that are robust against noise from the OCT laser source. Also integrated OCT system-probes are included that yield compact and robust electro-opto-mechanical systems along with polarization sensitive OCT systems.
1 . An optical coherence tomography probe, comprising:
a handpiece housing;
an optical window in the handpiece housing;
an interference signal fiber coupler in the handpiece housing that receives an optical coherence tomography (OCT) signal from an OCT analysis system and divides the OCT signal between a reference optical fiber arm and a signal optical fiber arm; and
an optical window in the handpiece housing through which the OCT signal from the signal optical fiber arm is transmitted to an object of interest and through which an object OCT signal is received from the object of interest and coupled into the signal optical fiber arm;
wherein the object OCT signal is mixed with the OCT signal from the reference optical fiber arm to generate an interference signal that is transmitted from the handpiece housing to the OCT analysis system.
2 . A probe as claimed in claim 1 , further comprising a handpiece coupler for coupling the handpiece housing to an umbilical that transmits the OCT signal to the handpiece housing from the OCT analysis system and the interference signal from the handpiece housing to the OCT analysis system.
3 . A probe as claimed in claim 1 , further comprising at least one control switch on the handpiece housing for controlling the OCT probe.
4 . A probe as claimed in claim 1 , wherein the reference arm reflector is a partial reflector that reflects less than 10% of the OCT signal to return back down the reference optical fiber arm.
5 . A probe as claimed in claim 1 , wherein the reference arm reflector is a highly reflecting that reflects greater than 90% of the OCT signal to return back down the reference optical fiber arm.
6 . A probe as claimed in claim 5 , further comprising an attenuator on the reference optical fiber arm that attenuates the OCT signal by greater than 90%.
7 . A probe as claimed in claim 1 , further comprising a scanning unit that receives the OCT signal from the signal optical fiber arm and scans the OCT signal over the object of interest.
8 . A probe as claimed in claim 7 , wherein the scanning unit comprises a scanning mirror that directs the OCT signal to the object of interest.
9 . A probe as claimed in claim 7 , wherein the scanning unit comprises a graded index lens for collimating the OCT signal.
10 . A probe as claimed in claim 1 , wherein the interference signal fiber coupler is not a 50/50 fiber coupler.
11 . A probe as claimed in claim 1 , wherein two OCT signal optical fibers transmit the interference signal to the OCT analysis system from the interference signal fiber coupler.
12 . A probe as claimed in claim 1 , wherein the interference signal fiber coupler is a 50/50 fiber coupler.
13 . A probe as claimed in claim 1 , wherein the interference signal fiber coupler is a polarization maintaining fiber coupler and the reference optical fiber arm comprises a polarization rotating element for rotating a polarization of the OCT signal on the reference optical fiber arm.
14 . A probe as claimed in claim 13 , wherein the polarization rotating element is a quarterwave plate.
15 . An optical coherence tomography method, comprising:
receiving an OCT signal from an OCT analysis system in an interference signal fiber coupler located within a handpiece housing and dividing the OCT signal between a reference optical fiber arm and a signal optical fiber arm;
transmitting the OCT signal on the signal optical fiber arm from the handpiece housing to an object of interest and receiving an object OCT signal from the object of interest into the handpiece housing and coupling the object OCT signal onto the signal optical fiber arm;
combining the object OCT signal with the OCT signal from the reference optical fiber arm to generate an interference signal; and
transmitting the interference signal from the handpiece housing to the OCT analysis system.
16 . An optical coherence tomography system, comprising:
a swept source laser for generating the OCT signal that is transmitted to a handpiece;
a detector system that detects the interference signal received from the handpiece; and
a controller that uses the response of the detector system to generate an image of an object of interest.
17 . A system as claimed in claim 16 , further comprising an amplitude reference detector; and a path matching fiber between the swept laser source and the amplitude reference detector for delaying the OCT signal detected by the amplitude detector system for a period corresponding to the optical delay to and from the handpiece.
18 . A system as claimed in claim 17 , further comprising a fiber combiner that receives the OCT signal from the swept source laser and divides the OCT signal between the path matching fiber and the handpiece.
19 . A system as claimed in claim 16 , wherein the detector system comprises:
polarization beam splitter for separating the interference signal into two polarizations;
a parallel detector for detecting the interference signal that is polarized parallel to the swept source laser; and
a perpendicular detector for detecting the interference signal that is polarized perpendicular to the OCT signal from swept source laser.
20 . A system as claimed in claim 16 , further comprising an anti-aliasing for filtering the output of the parallel detector and the perpendicular detector.
21 . A polarization sensitive optical coherence tomography probe, comprising:
a probe body cohandpiece housing;
an optical window in the handpiece housing;
an interference signal fiber coupler in the handpiece housing that receives an optical coherence tomography (OCT) signal from an OCT analysis system and divides the OCT signal between a reference optical fiber arm and a signal optical fiber arm; and
an optical window in the handpiece housing through which the OCT signal from the signal optical fiber arm is transmitted to an object of interest and through which an object OCT signal is received from the object of interest and coupled into the signal optical fiber arm;
wherein the object OCT signal is mixed with the OCT signal from the reference optical fiber arm to generate a interference signal that is transmitted from the handpiece housing to the OCT analysis system.