System and method for reducing post-surgical rainbow effect
View Patent ↗The disclosure relates to a pulsed laser system including a laser source that generates a laser beam, a scanner that controls the location of a beam focal point of the laser beam and also the location of a photodisruption formed at the beam focal point in a cornea of an eye, a computer that generates instructions to the laser source and scanner to direct the formation of a regular photodisruption pattern in the cornea, and a noise source that disturbs the location of each photodisruption to cause an irregular photodisruption pattern to form in the cornea, such that diffraction of light by the cornea after formation of the photodisruption pattern is decreased or avoided.
1. A pulsed laser system comprising:
a laser source configured to generate a laser beam;
a scanner configured to control the location of a beam focal point of the laser beam and the location of a photodisruption formed at the beam focal point in a cornea of an eye;
a computer configured to generate instructions to the laser source and the scanner to direct the formation of a regular photodisruption pattern in the cornea; and
a noise source separate from the computer, the noise source configured to disturb one or more control elements of the scanner to disturb the location of at least one photodisruption to cause an irregular photodisruption pattern to form in the cornea, regardless of the instructions that the scanner receives from the computer that direct the formation of the regular disruption pattern, such that diffraction of light by the cornea after formation of the photodisruption pattern is decreased or avoided, the noise source configured to disturb the one or more control elements by physically moving a control element of the one or more control elements of the scanner, the control element controlling the location of the at least one photodisruption wherein the noise source is a thermal noise source.
2. The pulsed laser system of claim 1 , wherein the laser source is a femtosecond laser.
3. The pulsed laser system of claim 1 , wherein the scanner comprises at least one transverse control element and at least one longitudinal control element.
4. The pulsed laser system of claim 3 , wherein the noise source is coupled to the at least one transverse control element or the at least one longitudinal control element.
5. The pulsed laser system of claim 1 , further comprising an electrical signal limiter to limit a distance the photodisruption is disturbed in any direction.
6. The pulsed laser system of claim 1 , wherein each photodisruption is disturbed a distance no more than 20% of the spacing between photodisruptions in a given direction in the regular photodisruption pattern.
7. The pulsed laser system of claim 1 , wherein a distance each photodisruption is disturbed is limited such that photodisruptions do not overlap.
8. The pulsed laser system of claim 1 , wherein the noise source is configured to disturb the one or more control elements of the scanner to disturb the series of locations of the beam focal point in an x, y, and z-dimension.