Sequential wavefront sensor

A method for detecting aberration of an incident wavefront, said method comprising:

• sequentially shifting an incident wavefront by a first displacement in a first dimension and a second displacement in a second dimension
• intercepting and selecting a portion of a shifted incident wavefront with an aperture;
• focusing the portion of the shifted incident wavefront selected by the aperture onto a position sensing device;
• and
• determining the two-dimensional deflection of the portion of the incident wavefront focused on the position sensing device from a reference point on the position sensing device.

A method for compensating aberrations of an incident wavefront, said method comprising:

• sequentially shifting an incident wavefront by a first displacement in a first dimension and a second displacement in a second dimension;
• intercepting and selecting a portion of the shifted incident wavefront with an aperture;
• focusing the portion of the shifted incident wavefront selected by the aperture onto a position sensing device;
• measuring the two-dimensional deflection of the focused portion of the shifted incident wavefront focused onto the position sensing device from a reference point on the position sensing device to determine the aberration of the incident wavefront;
• and
• forming a feedback criteria based on the two-dimensional deflection of the focused portion of the shifted incident wavefront.

A wavefront compensation system comprising:

• a wavefront scanning device adapted to sequentially shift an incident wavefront by a first displacement in a first dimension and a second displacement in a second dimension
• an aperture positioned to intercept and configured to select a portion the incident wavefront shifted by the sequential scanning device;
• a focusing element configured to focus the portion of the shifted incident wavefront selected by the aperture onto a position sensing device;
• with the position sensing device configured to indicate the two-dimensional displacement from a reference point of the portion of the shifted incident wavefront focused by the focusing element onto the position sensing device;
• a wavefront aberration analyzing device that generates a feedback signal based on detected locations of the sequentially selected portions of the shifted incident wavefront;
• and
• a wavefront compensation device for compensating aberrations in the wavefront that utilizes the feedback signal in a closed loop control system to activate compensation.

A sequential wavefront sensor comprising:

• a wavefront scanning device adapted to sequentially shift an incident wavefront so that an annular ring is sampled;
• an aperture positioned to intercept and configured to select a portion the incident wavefront shifted by the wavefront scanning device;
• a focusing element configured to focus the portion of the shifted incident wavefront selected by the aperture onto a position sensing device;
• and
• with the position sensing device configured to indicate the two-dimensional displacement from a reference point of the portion of the shifted incident wavefront focused by the focusing element onto the position sensing device.

A sequential wavefront sensor comprising:

• a wavefront scanning device adapted to sequentially shift an incident wavefront by a first displacement in a first dimension and a second displacement in a second dimension;
• a variable aperture positioned to intercept and configured to select a portion the incident wavefront shifted by the wavefront scanning device, with the size of the aperture being variable so that the sensitivity and resolution can be controlled;
• a focusing element configured to focus the portion of the shifted incident wavefront selected by the aperture onto a position sensing device;
• and
• with the position sensing device configured to indicate the two-dimensional displacement from a reference point of the portion of the shifted incident wavefront focused by the focusing element onto the position sensing device.

A system comprising:

• a position sensing device configured to indicate the two-dimensional displacement of an incident image spot;
• an aperture configured to pass through a portion of a wavefront to project an image spot onto the position sensing device;
• and
• a scanning device configured to sequentially direct any portion of an incident wavefront to pass through the aperture.

An apparatus comprising:

• an aperture disposed along an aperture plane;
• an optical system configured to replicate an incident wavefront onto the aperture plane,
• a wavefront positioning device, included in the optical system, configured to project the incident wavefront with a selected two-dimensional transversal displacement onto the aperture plane so that any portion of the projected replicate of the incident wavefront can be selected to pass through the aperture;
• a focusing element configured to focus the portion of the projected replicate of the incident wavefront selected to pass through the aperture onto a position sensing device;
• and
• with the position sensing device configured to indicate the two-dimensional displacement from a reference point of the portion of the incident wavefront focused by the focusing element onto the position sensing device.