System and method for scanning a beam of ultra-short pulse light
View Patent ↗An embodiment of a scanning optical system comprises: an optical source providing a beam of pulsed light of ultra-short pulse duration; a deflector for deflecting the beam through a scan angle; a lens system including a focusing objective for focusing the deflected beam; a dispersion compensating device for reducing dispersion-related distortion of a pulse of the beam by the lens system, the dispersion compensating device including a deformable, dispersive mirror and an actuator device for the mirror; and a controller for controlling the actuator device to change a shape of the mirror in accordance with the scan angle.
1. A scanning optical system comprising:
an optical source configured to provide a beam of pulsed light of ultra-short pulse duration;
a deflector configured to deflect the beam through a scan angle;
a lens system including a focusing objective configured to focus the deflected beam;
a dispersion compensating device configured to reduce dispersion-related distortion of a pulse of the beam by the lens system, the dispersion compensating device including a deformable, dispersive mirror and an actuator device for the mirror; and
a controller configured to control the actuator device to change a shape of the mirror in accordance with the scan angle.
2. The optical system of claim 1 , wherein the deformable, dispersive mirror has a multilayer structure providing a dispersion characteristic that varies with position on a reflecting surface of the mirror.
3. The optical system of claim 2 , wherein the multilayer structure is configured to introduce at least one of a non-uniform group delay, a non-uniform group delay dispersion, and a non-uniform third-order dispersion across the reflecting surface.
4. The optical system of claim 2 , wherein the dispersion compensating device further includes a bulk compensator having a spatially uniform dispersion characteristic for compensating a bulk of at least one of a group delay and a group delay dispersion introduced by the lens system.
5. The optical system of claim 1 , wherein the optical source is a laser source and the light has a center wavelength suitable for creating incisions in human eye tissue.
6. A scanning optical system comprising:
an optical source configured to provide a beam of pulsed light of ultra-short pulse duration;
a deflector configured to deflect the beam through a scan angle;
a lens system including a focusing objective configured to focus the deflected beam;
a deformable mirror;
an actuator device for the mirror; and
a controller for controlling configured to control the actuator device to change a shape of the mirror in accordance with the scan angle.
7. The scanning optical system of claim 6 , wherein the deformable mirror is non-dispersive.
8. The scanning optical system of claim 7 , including a dispersion compensating device for reducing dispersion-related distortion of a pulse of the beam by the lens system.
9. The scanning optical system of claim 1 , wherein changes of the shape of the mirror as instructed by the controller are designed to accommodate variations of the spatial distribution of a group delay of the optical system, which variations come with different scan angles.
10. A scanning method comprising:
providing a beam of pulsed light of ultra-short pulse duration;
deflecting the beam through a scan angle;
focusing the deflected beam with a focusing objective;
providing a deformable mirror; and
controlling a shape of the deformable mirror in accordance with the scan angle to compensate at least partially variations of the spatial distribution of a group delay of the focusing objective versus different scan angles.