Flashcards in Effect Of Diffraction On Retinal Image Deck (30):
Production of 3d images of objects
-maintain 'phase relationship' of two waves constant all through out
-extremely complicated interference
A hologram records
-light from the object (intensity)
-phase-difference between the 'reference' beam and beam scattered from the object
_________ causes interference pattern to be formed producing an image with 3D information
Unlike conventional imaging, in holographic imaging, light from each point on the object will do what?
Reach all points on the film.
You can break a small piece off of holography film and still see entire image
Requires a __________ to view the holographic image recording.
Interference pattern recording on the film acts as _____________
Real image on holographic film
M=0. Usually not viewed
Virtual image on holographic film
Virtual image behind the film are viewed, with light coming from it exactly same way light came from the actual object when the film was exposed
Hologram viewed horizontally
You will see 3D image
Hologram viewed vertically
You will see different colors
What are the types of holograms
Transmission and reflection
To analyze light passing through a slit and diffracted by a grating when collimated light is incident on it
Diffraction grating spectrometer
-used to identify planets
How does diffraction affect the retinal image?
For the eye, only a section passes through the pupil; the iris is an obstruction that diffracts the light. This diffraction blurs the image. For a system limited only by diffraction, the image radius for a point object is 1.22lambda/d
As pupil size increases, point spread function ______
To fix diffraction affects in small pupil less than 3mm, use ________
Gaussian filter for adopization
What do you use in larger pupil to fix diffraction effects?
What causes the image to appear different than the object in aberrated lens?
Diffraction and aberrations
Aberrations increase with ________ pupil size
Diffraction decreases with __________ pupil size
Best retinal image quality is provided by a ___mm pupil
____ controls impact of ocular aberrations and diffraction on retinal image quality
You can have perfect optics, but what ultimately limits image quality?
Corneal transparency is a __________ phenomenon
When is the cornea opaque?
An array of equally spaced collagen fibrils acts as a _______, scattering light into discrete directions
A fibril spacing (d) smaller than the wavelength of light (lambda) will make the fibrils ____________ as light passes through undeviated
If d< lambda then theta>90 degrees for all m>0. Therefore no diffraction orders exist except m=o. Under this condition, the fibrils diffract no light and appear transparent
Caused by cataracts, angle closure glaucoma, edema
-diffraction from regularly spaced epithelial or lens fiber cells
The ciliary corona is an entoptic _____________ phenomenon