Patent ID: 7374287

Claim:
A scanning laser opthalmoscope apparatus for projecting a two-dimensional pattern of light of variable intensity and resolution onto the retina of an eye comprising the elements of: a laser source means, emitting a beam of light with a wavelength in the visible range and having a beam diameter that is large enough and depth of focus that is large enough to transmit and focus said beam within said apparatus over a distance; a first focusing means for reducing substantially the beam diameter and reducing accordingly the depth of focus of said beam of light; an acousto-optic modulating means comprising crystal optics with an optical axis and of certain small dimension wherein sound waves propagate with a certain velocity, and electronic driver means emitting a modulated radio signal of certain frequency for creating said sound waves, said first focusing means and said crystal optics placed at a distance from each other and in such manner that said beam of light will focus optimally inside said crystal optics at an angle relative to said optical axis, said angle determined by said wavelength, said radio frequency and said sound velocity, and said radio frequency high enough to cause said sound waves to diffract said beam of light of reduced beam diameter efficiently in a minimum amount of time into a first order modulated beam of light of reduced beam diameter; a beam expanding means for enlarging the beam diameter of said first order diffracted and modulated beam of light leaving said crystal optics at said angle relative to said optical axis to enable again further focusing within said apparatus over a distance; a scanning means including horizontal polygon scanning means, vertical scanning means and second focusing means, to direct and focus said modulated and first order diffracted beam of light onto said retina of an eye, whereby a very high modulation bandwidth is obtained for the projection of said two-dimensional pattern of light relative to the bandwidth of imaging for said apparatus.