Single-chip optical coherence tomography device
AssigneeAcademisch Medisch Centrum
InventorBakiye Imran Avci
Life of this patent
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Abstract
A high-performance single-chip, integrated-optics-based OCT system is disclosed, where the length of the reference arm is digitally variable. The reference arm includes a plurality of switch stages comprising a 2×2 tunable wavelength-independent waveguide switch that can direct an input light signal onto either of two different-length output waveguides. In some embodiments, the directional couplers are thermo-optic based. Some embodiments include a solid-state scanning system for scanning a sample signal along a line of object points on the sample under test.
Claims20
An integrated-optics-based optical coherence tomography (OCT) system having a sample arm and a reference arm, the OCT system comprising a photonic lightwave circuit (PLC) that is monolithically integrated on a substrate, wherein the PLC includes:
- (i) a coupler for distributing an input light signal into a sample signal on the sample arm and a reference signal on the reference arm;
- (ii) a beam combiner for combining the reference signal and a reflected signal from a sample to generate an interference signal, the reflected signal being based on the sample signal and the sample;
- and
- (iii) the reference arm, wherein the reference arm is operative for conveying the reference signal from the coupler to the beam combiner, and wherein the reference arm includes a delay controller that is operative for digitally controlling the length of the reference arm within a range from a minimum length to a maximum length;
- a first photodetector configured to provide an output signal based on the interference signal;
- a second photodetector configured to provide a dispersion signal that is based on a first signal received from the delay controller, wherein the first signal includes at least a portion of the reference signal;
- and
- a processor that is operative for compensating a dispersion mismatch between the reference arm and sample arm based on the dispersion signal.
A method for performing optical coherence tomography (OCT), the method comprising:
- providing a planar-lightwave circuit (PLC) that includes a coupler, a reference waveguide, a delay controller, and a beam combiner, wherein the PLC is monolithically integrated on a substrate;
- distributing an input light signal received at the coupler into a sample signal on a sample arm and a reference signal on a reference arm, wherein the reference arm includes the reference waveguide and the delay controller;
- providing the sample signal to a sample;
- receiving a reflected signal at the beam combiner, wherein the reflected signal is based on the sample signal and the sample;
- conveying the reference signal from the coupler to the beam combiner via the reference waveguide and the delay controller;
- combining the reference signal and the reflected signal at the beam combiner to generate an interference signal;
- providing an output signal from a first photodetector, wherein the output signal is based on the interference signal;
- controlling the delay controller to digitally control a length of the reference arm within a range from an initial length to a maximum length;
- directing a dispersion signal to a second photodetector, wherein the dispersion signal includes at least a portion of the reference signal;
- and
- compensating a dispersion mismatch between the reference arm and sample arm based on the dispersion signal.
Dependencies are inferred from the claim text.