Ophthalmic range finding
Systems and methods for analyzing the anatomy of a patient's eye with circular or rotated polarized laser beams, or with laser beams of different wavelengths are disclosed. One system includes a polarization beam-splitter and a quarter-wave plate, wherein the quarter-wave plate is configured to circularly rotate a laser beam received from a laser that is transmitted and passes through the polarization beam-splitter, and to transform a circularly rotated back-reflected beam to a linearly polarized laser beam that is perpendicular to the beam that was transmitted through the polarization beam-splitter. Substantially all of the back-reflected beam is directed to a photo-detector for analysis. A Faraday rotator subsystem may be substituted for a polarization beam-splitter. An optical system including a laser that generates a laser beam of a first wavelength for therapeutic treatment, and another laser that generates a laser beam of a second wavelength for measurement is also disclosed.
1. A system for analyzing a patient's eye comprising:
a laser configured for directing a pulsed laser beam along a path;
an optical beam-splitting device disposed along the path from the laser, the optical beam-splitting device configured to polarize and rotate the polarity of the laser beam;
an objective component including a focusing lens to focus the laser beam within the eye;
a sensor oriented along the path, wherein the sensor receives a back-reflected laser beam from the eye, and generates a signal corresponding to that laser beam; and
a computing device communicatively coupled with the sensor and configured to receive the signal, wherein the computing device determines a position of an anatomical feature of the eye based on the signal.
2. The system of claim 1 , wherein the optical beam splitting device comprises:
a polarization beam splitter configured to transmit a laser beam oriented in a first linear direction; and
a quarter-wave plate configured to rotate in a first circular direction the laser beam transmitted through the polarization beam splitter toward the eye, and to transform the rotation of the back-reflected laser beam from a second circular direction to a second linear direction.
3. The system of claim 1 , wherein the optical beam-splitting device comprises a partially reflecting and a partially transmitting mirror.
4. The system of claim 1 , wherein the optical beam-splitting device comprises a Faraday rotator subsystem configured to polarize and rotate the laser beam along the path from the laser.
5. The system of claim 4 , wherein the Faraday rotator subsystem comprises a polarization beam-splitter and a Faraday rotator.
6. The system of claim 4 , wherein Faraday rotator subsystem comprises a Faraday optical isolator.
7. The system of claim 1 , wherein the sensor is selected from the group consisting of a CCD camera, a photodiode detector, and a Shack-Hartmann wavefront sensor.
8. The system of claim 1 , wherein the sensor comprises a lens, a pinhole, and a photo detector.
9. The system of claim 1 , wherein the laser comprises a non-ultraviolet, ultra-short pulsed laser.
10. A system for analyzing an eye of a patient comprising:
a laser configured for directing a pulsed laser beam along a path;
a polarization beam-splitter disposed along the path from the laser and configured to transmit a laser beam oriented in a first linear direction;
a quarter-wave plate disposed between the polarization beam splitter and the eye, and configured to rotate in a first circular direction the laser beam that is transmitted by the polarization beam splitter toward the eye, and to transform the rotation of a back-reflected laser beam from a second circular direction to a second linear direction;
an objective component including a focusing lens to focus the laser beam within the eye;
a confocal system comprising a lens and a pinhole oriented to focus the back reflected laser beam from the eye, wherein the back-reflected laser beam is transmitted to the confocal system by the polarization beam splitter;
a sensor oriented along the path, wherein the sensor receives the back-reflected laser beam from the confocal system and generates a signal corresponding to that laser beam; and
a computing device communicatively coupled with the sensor and configured to receive the signal, wherein the computing device determines a position of an anatomical feature of the eye based on the signal.
11. The system of claim 10 , wherein the sensor is selected from the group consisting of a CCD camera, a photodiode detector, and a Shack-Hartmann wavefront sensor.
12. The system of claim 10 , wherein the laser comprises a non-ultraviolet, ultra-short pulsed laser.
13. A system for analyzing an eye of a patient comprising:
a laser configured for directing a laser beam along a path;
a Faraday rotator subsystem configured to polarize and rotate the laser beam along the path;
an objective component including a focusing lens to focus the laser beam within the eye;
a confocal system comprising a lens and a pinhole oriented to focus a back laser beam energy from the eye, wherein the back-reflected laser beam is transmitted to the confocal system by the Faraday rotator subsystem;
a sensor oriented along the path, wherein the sensor receives the back-reflected laser beam from the confocal system and generates a signal corresponding to that laser beam; and
a computing device communicatively coupled with the sensor and configured to receive the signal, wherein the computing device determines a position of an anatomical feature of the eye based on the signal.
14. The system of claim 13 , wherein the Faraday rotator subsystem comprises a polarization beam splitter and a Faraday rotator.
15. The system of claim 13 , wherein Faraday rotator subsystem comprises a Faraday optical isolator.
16. The system of claim 13 , wherein the sensor is selected from the group consisting of a CCD camera, a photodiode detector, and a Shack-Hartmann sensor.
17. The system of claim 13 , wherein the laser comprises a non-ultraviolet, ultra-short pulsed laser.
18. A system for analyzing an eye of a patient comprising:
a first laser configured for directing a first laser beam along a path;
a second laser configured for directing a second laser beam along the path, the second laser beam having a shorter wavelength than the first laser beam;
a beam-splitter configured to reflect the second laser beam along the path toward the eye, and to transmit a back reflected second laser beam from the eye toward a sensor;
a dichroic mirror configured to reflect the second laser beam along the path toward the eye and to transmit the first laser beam along the path toward the eye;
an objective component including a focusing lens to focus the first and second laser beams within the eye;
a sensor oriented along the path, wherein the sensor receives the back reflected second laser beam and generates a signal corresponding to that laser beam; and
a computing device communicatively coupled with the sensor and configured to receive the signal, wherein the computing device determines a position of an anatomical feature of the eye based on the signal.
19. The system of claim 18 , wherein a portion of the second laser beam is transmitted through the beam-splitter and the system further comprises a beam dump that absorbs the portion of the second laser beam transmitted through the beam splitter.
20. The system of claim 18 , wherein the sensor is selected from the group consisting of a photodiode detector, a CCD camera, and a Shack-Hartmann wavefront sensor.
21. The system of claim 18 , wherein the first laser comprises a non-ultraviolet, ultra-short pulsed laser.