Method and apparatus for recording three-dimensional distribution of light backscattering potential in transparent and semi-transparent structures

An apparatus for measuring the distribution profile of a light scattering potential of an object defining at least one reference site and a plurality of measurement sites, the apparatus comprising:

• (b) a plurality of light beams comprising at least one reference light beam and at least one measurement light beam, the light beams having short coherence length;
• (c) at least one frequency shifter positioned in at least one beam path of the light beams;
• (d) an optics system including at least one focusing lens, the optics system directing the measurement light beam to a measurement site and directing the reference light beam to the reference site, the optics system directing reflected light from a selected measurement site and from the reference site to a receiver generating an output signal;
• (e) an optical scanner positioned in at least the measurement light beam and directing the measurement light beam to at least one selectable measurement site;
• and
• (f) at least two beam splitters, the measurement light beam and the reference light beam substantially overlapping at the beam splitters.

An apparatus for measuring the distribution profile of a light scattering potential of a fundus layers of the eye, comprising:

• (a) a light source generating a plurality of light beams including at least one reference light beam and at least one measurement light beam;
• (b) at least one frequency shifter positioned in at least one beam path of the light beams;
• (c) a plurality of optics directing the measurement light beam to a measurement site and the reference light beam to the reference site, the optics further directing reflected light from a selected measurement site and from the reference site to a receiver generating an ouput signal;
• (d) at least one optical scanner positioned in at least the measurement light beam to direct the measurement light beam to at least one selectable measurement site;
• and
• (e) at least one beam path compensator element in the measurement light beam, such that a coherence layer from which the signal is derived has a curvature which is substantially matched with a curvature of the fundus layers when the measurement light beam is scanned by the optical scanner.

A method for measuring the distribution profile of light scattering potential of an object, comprising:

• (a) generating light beams with short coherence length;
• (b) scanning at least one of the light beams in at least one dimension with at least one optical scanner;
• (c) shifting the optical frequency of at least one of the light beams with a non-moving frequency shifter;
• (d) directing the light beams toward the object with an optics system including a first focusing lens in the measurement light beam such that the measurement light beam forms a focal point at a measuring site, and a second focusing lens in the reference light beam such that the reference light beam forms a focal point at a reference site, the measurement site and the reference site being selectable at different focal planes defined by the object;
• (e) directing reflected light beams from the object to a receiver;
• (f) controlling at least one path delay unit such that a travel distance of the measurement light beam and a travel distance of the reference light beam are substantially matched;
• and
• (g) generating a signal using the receiver, the signal having a beat frequency defined at least in part by the controlling act, whereby axial motion of the object relative to an incident direction of the light beams with respect to the object equally affects the reference light beam and the measurement light beam.

A method of measuring the distribution profile of light scattering potential of an object, comprising:

• (a) generating light beams with short coherence length;
• (b) scanning at least one of the light beams in at least one dimension with at least one optical scanner;
• (c) shifting the optical frequency of at least one of the light beams with a non-moving frequency shifter;
• (d) directing the light beams toward the object with a plurality of optics;
• (e) controlling at least one path delay unit such that the travel distance of the measurement light beam and the travel distance of the reference light beam are matched;
• (f) generating a signal defining a beat frequency established at least in part by the controlling act;
• and
• (f) inserting a polarizer and a quarter wave plate in a light beam path including the frequency shifter, such that at least the measurement light beam is directed to avoid passing the frequency shifter in its return from the object.

A method of measuring the distribution profile of light scattering potential of an object, comprising:

• (a) generating light beams with short coherence length;
• (b) scanning at least one of the light beams in at least one dimension with at least one optical scanner;
• (c) shifting the optical frequency of at least one of the light beams with a non-moving frequency shifter;
• (d) directing the light beams towards the object with a plurality of optics comprising a first focusing lens in the measurement light beam such that the measurement light beam forms a focal point at a measurement site, and a second focusing lens in the reference light beam such that the reference light beam forms a focal point at a reference site, the measurement site and the reference site being selected at different focal planes defined by the object;
• (e) controlling at least one path delay unit such that a travel distance of the measurement light beam and a travel distance of the reference light beam are matched;
• (f) generating a signal defining a beat frequency established at least in part by the controlling act;
• and
• (g) directing the measurement light beam and the reference light beam to substantially overlap each other at at least two beam splitters in incident and reflected propagation directions relative to the object.

A method of measuring the distribution profile of light scattering potential of a fundus layers of the eye, comprising:

• (a) generating light beams with short coherence length;
• (b) scanning at least one of the light beams in at least one dimension with at least one optical scanner;
• (c) shifting the optical frequency of at least one of the light beams with a non-moving frequency shifter;
• (d) directing the light beams towards the eye using a plurality of optics;
• (e) controlling at least one path delay unit such that a travel distance of the measurement light beam and a travel distance of the reference light beam are matched;
• (f) generating a signal defining a beat frequency established at least in part by the controlling act;
• and
• (g) inserting at least one path compensator element in the measurement light beam path such that a coherence layer from which the signal is derived has a curvature that substantially matches the curvature of the fundus layers of the eye when the measurement light beam is scanned by the optical scanner.