Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision Both sides next revision
hardware:scanner [2018/08/23 20:21]
Jon Daniels [MEMS limitations] 		hardware:scanner [2019/01/11 05:34]
Jon Daniels [MEMS limitations]
Line 31: Line 31:
 Larger MEMS mirrors are available and may be useful to achieve higher illumination NA when required.  However, the larger mirrors usually have a lower resonance so cannot be driven as fast.   Larger MEMS mirrors are available and may be useful to achieve higher illumination NA when required.  However, the larger mirrors usually have a lower resonance so cannot be driven as fast.  
  
-An arcane optical effect called "bow" that occurs when the axis of rotation isn't orthogonal to the plane made by the incoming/outgoing beams.  Since we have a 2D mirror, only one of the rotation axes can be made perpendicular to the beam plane and the other axis unavoidably suffers from this bow problem.  The resulting effect is a slight optical coupling of the axes, on the order of a few percent over the entire mirror travel for a standard scanner.  The Tiger controller firmware compensates for the effect automatically in internal mode and a per-axis compensation factor can be set (''ERROR'' command).  With a cylindrical lens, the "ideal" axis can be set to be either the line axis (allowing you to perfectly smear out the Gaussian intensity profile within the plane) or else the slice axis (allowing you to move the light sheet to create a stack in piezo/slice synchronous scan mode without tilting the light sheet), but not both simultaneously.+An arcane optical effect called "bow" that occurs when the axis of rotation isn't orthogonal to the plane made by the incoming/outgoing beams.  Since we have a 2D mirror, only one of the rotation axes can be made perpendicular to the beam plane and the other axis unavoidably suffers from this bow problem.  The resulting effect is a slight optical coupling of the axes, on the order of a few percent over the entire mirror travel for a standard scanner.  The Tiger controller firmware compensates for the effect automatically in internal mode and a per-axis compensation factor can be set (''ERROR'' command).  With a cylindrical lens, the "ideal" axis can be either the line axis (allowing you to perfectly smear out the Gaussian intensity profile within the plane) or else the slice axis (allowing you to move the light sheet to create a stack in piezo/slice synchronous scan mode without tilting the light sheet), but not both simultaneously.  This has to be set in the factory during scanner assembly, and unless otherwise specified the latter option is chosen, which also corresponds to having the cylindrical lens scanner oriented in exactly the same manner as a Gaussian beam scanner.

Trace: