Large diopter range real time sequential wavefront sensor
Example embodiments of a large dynamic range sequential wavefront sensor for vision correction or assessment procedures are disclosed. An example embodiment includes first and second optically coupled 4F relays and a variable focus lens disposed substantially at the image plane of the first 4F relay and the object plane of the second 4F relay.
1. A large diopter range sequential wavefront sensor for vision correction or assessment procedures comprising:
a first optical wavefront relay system including first and second lenses, each lens having a diameter, a focal length and an optical axis, with the first optical wavefront relay system configured to relay an incident wavefront from a first object plane in a first object space to a first wavefront image plane in a first wavefront image space along a first beam path where the focal lengths and diameters of the first and second lenses are selected to guide an incident wavefront relay beam having a large diopter range at the first object plane to the first wavefront image plane;
a second optical wavefront relay system including third and fourth lenses, each lens having a diameter, a focal length and an optical axis, with the second optical wavefront relay system having a second object plane in a second object space that is substantially at the first wavefront image plane, and configured to further relay the incident wavefront from the first wavefront image plane to a second wavefront image plane in a second wavefront image space along a second optical path, with the third lens configured to guide the wavefront relay beam to a Fourier transform plane located between the third and fourth lenses;
a variable focal length lens disposed substantially at the second object plane in the second object space, with the variable focus length lens being substantially conjugate to the first object plane and the second wavefront image plane and configured to dynamically change the sphero-diopter value of the wavefront when it is relayed from the first object plane to the second wavefront image plane;
a reflective beam shifting element disposed substantially at the Fourier transform plane located between the third and fourth lenses, positioned along the optical axis of the third lens to intercept substantially the entire wavefront relay beam over a desired large diopter range and oriented to fold the second optical path at a folding angle having a magnitude that prevents a wavefront beam reflected from being intercepted by the third lens;
a wavefront sampling aperture positioned at or near the second wavefront image plane; and
an image spot position sensing device positioned behind the sampling aperture.
2. A wavefront relay optical apparatus comprising:
a first 4F optical relay including first and second lens and configured to relay a wavefront from a first object plane to a first image plane;
a second 4F optical relay including third and fourth lenses configured to relay a wavefront from a second object plane to a second image plane, where the first and second 4F optical relays are disposed so that the second object plane and the first image plane are located at about the same position; and
a variable focal length lens positioned substantially at the second object plane and configured to change the sphero-diopter value of the wavefront when it is relayed from the first object plane to the second wavefront image plane.
3. The wavefront relay optical apparatus of claim 2 wherein there is a Fourier transform plane in the second 4F optical relay and further comprising:
a beam shifting element disposed at about the Fourier transform plane so that the beam shifting element intercepts substantially the entire wavefront relay beam.