Optics Review Flashcards
What is a light wave?
A wave of electric and magnetic fields
What is the electromagnetic spectrum?
It consists of all the different wave lengths of electromagnetic radiation
What are the types of radiation from low to high energy?
Radio, microwaves, infrared, visible, ultraviolet light, x-rays, gamma rays
Examples of radio waves
Radio, TV signal, cell phone, radar
Examples of microwaves
Telecommunications, microwave ovens
Examples of infrared light
Remote control, lasers, heat detection
Examples of visible light
Human vision, rainbows, visible lasers
Examples of ultraviolet light
UV lasers, “black” light
Examples of x-rays
Medical imaging, cancer treatment, security equipment
Examples of gamma rays
Cancer treatment
What does SALT stand for?
Size, Attitude, Location, Type
What is regular (specular) reflection of light?
On shiny surfaces, light reflects following law of reflection, a clear image is seen
What is diffuse reflection of light?
On rough surfaces, the reflection of waves becomes irregular. Light spreads and no clear image forms
Colours that make up visible spectrum, low to high
Red, orange, yellow, green, blue, indigo, violet
What are the two kinds of light sources?
Luminous- object gives off own light, Non-Luminous- object doesn’t give off own light
What are the luminous sources of light?
Incandescence, Fluorescence, Phosphoresence, Chemiluminescence, Triboluminesence
Incandescence
Light given off due to high temperature
Fluorescence
Chemical gives off light when hit by invisible high energy light waves
Phosphoresence
Chemical gives off light when hit by high energy light waves and stay luminous for long time
Chemiluminescence
Chemical reactions that give off light with next to no heat
Bioluminescence
When living things produce light
Triboluminescence
When certain crystals (sugar) are scratched, crushed, or rubbed, light is produced
LASERS
Light Amplification by Stimulated Emission of Radiation: light is very intense and the same colour, beam stays together
What is refraction?
When a light wave travels from one transparent medium into another, the velocity of the light waves change
Index of Refraction
n=c/v, c- speed of light in vacuum, v- speed of light in medium. c= 3.0x10^8m/s
Law of Refraction
When going from fast to slow, the ray will bend toward the normal, when going from slow to fast, the ray will bend away from the normal
Snells Law
n1 sin theta1 = n2 sin theta2
Total Internal Reflection
When a wave travels from slow to fast at a large angle of incidence, the wave can be trapped in the slow medium
What are some uses of Total Internal Reflection?
Periscope, Binoculars, Bike reflectors
What is the critical angle and how do you calculate it?
The angle of incidence that results in an angle of refraction 90 degrees to the normal. n1 sin thetaC = n2 sin90
What is a Lens?
A thin transparent piece of glass or plastic that has at least one curved side.
What are the four different types of lenses?
Biconvex, Biconcave, Plano convex, Plano concave
What are the two basic lens types?
Converging and diverging
