BOOK_CONTENT
From Adaptive Optics for Vision Science

10.3.6   Raster Scanning

Two mirrors are generally used to scan the focused spot in a raster pattern
on the retina. One mirror scans the line, defining the line rate, and the other
scans vertically, to set the frame rate. For the line scanner, an SLO can
use a polygon scanner or a galvanometric scanner. The ratio of the line scan
frequency to the vertical scan frequency defines the number of lines per
frame.

Two important considerations in the optical system are the beam size and
the scan angle at the location of the eye. As described in an earlier section,
the pupil size at any conjugate plane is easily computed by multiplying the
size of one pupil by the product of the magnifications of the telescopes that
lie between the two planes. The opposite occurs with field angle, since, as the
beam size is reduced, the scan angle enlarges. This is an invariant in the
optical system and is governed by the following equations:

 

where ma..z is the product of the magnifications of the telescopes between the
conjugate planes, a and z.

These considerations bear on the selection of the scanner. For example, if
the desired...


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Topics of Interest

10.3.7   Light Detection The light from the retina is descanned and is focused onto a confocal pinhole. Choosing the size of the confocal pinhole is important as it plays a role in governing the...

10.3.3   Light Path The light path in an AOSLO can be thought of as a series of telescopes that relay the light to the various elements that act on the beam. For example, wavefront sensing (p6 in...

4.3.6 Passive Scanning for Remote Sensing Figures 1.1 and 1.2 at the beginning of this work identify, respectively, active and passive scanning. The distinctions between the two appear in the...

4.6.1 Scanner-Lens Architecture Objective lens complexity (given wavelength, beamwidth, and scan angle) relates primarily to its orientation before or after the scanner. This is introduced and...

4.4.2 Implementation of Holographic Scanners It is informative to consider some earlier holographic scanners and their relationship to to contemporary designs. An example of one of the first systems...