Optics Properties of Light: Wavefronts and Vergence

That light ----- when it travels from one material into another

refract (bends)

lenses and mirrors can ______ light and can change the ____ and ______ of the image we see

refract

size and orientation

Prisms can

change the direction of light as well as split white light into its colored wavelengths

Vergence

is how light rays behave toward one antohet

diverging light

two ligth rays that travel away from each other

converging light

two light rays that traveling toward each other

when 2 rays of light moving apart the light becomes ______ bright with distance and time

less

the farther the screen is from the light source, the

dimmer the light gets

we are losing brightness

When we have rays of light moving toward each other, the light becomes ______ with distance and time

brighter

divergence

light gets less bright as it travels so it gets a minus sign

convergence

light gets brighter as it travels so it gets a plus sign

2 parallel rays of light have ______ vergence

no

point source

light starts at a point source

very tiny point of light

give off light

the light travels away from the point source

equally in all directions like a way

a point source will ALWAYS give off -_____ light

diverging

The wavefront is ____ close to the center

steeper (more curved --> smaller circle)

Wavefront is ___ farther from the center

flatter (less curved --> larger circle)

The curvature of a wavefront of a measure of its

vergence

more curve

more vergence

less curve

less vergence

short radius

wavefront is close to the center, steeper

more curve

more vergence

long radius

wavefront is further from center

there is an ______ relationship between radius and vergence

inverse

Vergence equation

V = n/r

r is measured from

the surface of the wavefront to the center

positive r

left to right

negative r

right to left

diverging wavefronts have a ---- radius

minus

converging wavefronts have a ---- radius

plus

Index of refraction

a measure of the amount a ray of light bends when it passes from one medium to another

as light travels into a medium of higher index (air to water), it

slows down

as the index of the plastics increases, the lens becomes _______ therefore

more efficient at bending light

therefore ghigh index materials can be made thinner

Basic Plastic CR-39

indez of 1.53

Polycarbonate

1.59

this is softer material: can scartch easily

very impact resistance

safety glassess and chidlrens

We can get hi nidex plastics in n=

1.6

1.67

1.74

as rx increases we reccomend

higher index to improve cosmetic appearance

(thinner for same rx)7

if we see -V the minus sign means

diverging light

we just look at the absolute value

at greater distance,

less mergence

flatter wavefront

optical systems change

the vergence of the light