Combination of mirror images to improve signal quality for contact lenses
View Patent ↗A method and system to provide for increased signal intensity and improved signal quality in Fourier-domain optical coherence tomography (FDOCT) by capturing the real and virtual images of an object being imaged by FDOCT in sequence or consecutively.
1. A method for acquiring real and virtual images of an object, comprising:
providing a Fourier-domain optical coherence tomography imaging system;
generating a reference beam having a pathway, and the reference beam having two different pathlengths;
modifying the pathlength of the reference beam; and
acquiring the real image and virtual image of the object consecutively;
and thereafter
superimposing the acquired real and virtual images to achieve more uniform signal across the scan depth range.
2. The method of claim 1 wherein the step of modifying the pathlength of the reference beam comprises providing an optical chopper disposed along a portion of the reference beam pathway, the optical chopper comprising a movable refractive medium, and moving the movable refractive medium into and out of the optical coherence tomography reference beam pathway.
3. The method of claim 2 wherein the movable refractive medium is a glass lens.
4. The method of claim 1 wherein the step of modifying the pathlength of the reference beam comprises providing a fiber-optic switch disposed along a portion of the reference beam pathway and splitting the reference beam into at least a first channel and a second channel with the fiber-optic switch.
5. The method of claim 4 further comprising a first movable or fixed mirror positioned within the first channel, and a second movable or fixed mirror positioned within the second channel.
6. The method of claim 4 wherein the fiber-optic switch switches the reference beam between the first channel and the second channel substantially continuously.
7. The method of claim 6 wherein the fiber-optic switch switches the reference beam between the first channel and the second channel at a rate of about 50 micro seconds or faster.
8. The method of claim 1 wherein the step of modifying the pathlength of the reference beam comprises providing a linear stage disposed along a portion of the reference beam pathway, the linear stage comprising a reference reflector, and moving the reference reflector to change the pathlength of the reference beam.