1 / 55

680 likes | 1.23k Views

Geometric Optics. Mirrors, light, and image formation. Geometric Optics. Understanding images and image formation, ray model of light, laws of reflection and refraction, and some simple geometry and trigonometry The study of how light rays form images with optical instruments.

Download Presentation
## Geometric Optics

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**Geometric Optics**Mirrors, light, and image formation**Geometric Optics**• Understanding images and image formation, ray model of light, laws of reflection and refraction, and some simple geometry and trigonometry • The study of how light rays form images with optical instruments**Reflection and refraction on plane mirrors**Reflection and Refraction at a plane Surface**Key terms**• Anything from which light rays radiate • Object • Anything from which light rays radiate that has no physical extent • Point object • Real objects with length, width, and height • Extended objects**Image formation by a Plane mirror**V θ θ θ θ M’ M s s’**Image formation by a Plane mirror**• M is the object and M’ is the virtual image • Ray MV is incident normally to the plane mirror and it returns along its original path • s= object distance • s’= image distance • s=-s’**Image formation by a Plane mirror**• Sign rules For the object distance: • When the object is on the same side of the reflecting or the refracting surface as the incoming light, s is positive For the image distance: • When the image is on the same side of the reflecting or the refracting surface as the outgoing light, s’ is positive**Image of an extended object**V’ V Q’ Q θ θ y y’ θ θ M θ M’ s s’**Image of an extended object**• Lateral magnification • Ratio of image height to object height • M=y’/y • Image is erect • m for a plane mirror is always +1 • Reversed means front-back dimension is reversed**Reflection on Concave and Convex mirrors**Reflection at a Spherical Surface**Reflection at a Concave Mirror**V C P P’**Graphical Methods for Mirrors**Image formation on spherical mirrors**Graphical Method**• Consists of finding the point of intersection of a few particular rays that diverge from a point of the object and are reflected by the mirror • Neglecting aberrations, all rays from this object point that strike the mirror will intersect at the same point**Graphical Method**• For this construction, we always choose an object point that is not on the optic axis • Consists of four rays we can usually easily draw, called the principal rays**Reflection at a Concave Mirror**V F C s at infinity s’= R/2**Reflection at a Concave Mirror**• All reflected rays converge on the image point • Converging mirror • If R is infinite, the mirror becomes plane**Reflection at a Concave Mirror**V F C s’ at infinity s= R/2**Reflection at a Concave Mirror**1/s+ 1/s’= 1/f Object image relation, spherical mirror**Reflection at a Convex Mirror**F C s’ or s= R/2 s or s’ at infinity**Image formation on spherical mirrors**• Sign rules For the object distance: • When the object is on the same side of the reflecting or the refracting surface as the incoming light, s is positive; otherwise, it is negative**Image formation on spherical mirrors**• Sign rules For the image distance: • When the image is on the same side of the reflecting or the refracting surface as the outgoing light, s’ is positive; otherwise, it is negative**Image formation on spherical mirrors**• Sign rules: For the radius of curvature of a spherical surface: • When the center of curvature C is on the same side as the outgoing light, the radius of curvature is positive, otherwise negative**Reflection at a Convex Mirror**• The convex side of the spherical mirror faces the incident light • C is at the opposite side of the outgoing rays, so R is neg. • All reflected rays diverge from the same point • Diverging mirror**Refraction at spherical interface**Refraction at a Spherical Surface**Refraction at a Spherical Surface**na/s + nb/s’=0 At a plane refracting surface**Biconcave and biconvex thin lenses**Graphical Method for Lenses

More Related