Optical Devices

Optical Devices

By Stacy King

Light as a Particle

When a photon hits a metalic surface causing an electron (negative charged sub atomic particle) to be released​

• photoelectron​

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Photo Electric Effect

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Light reflects or refracts as a wave but scatters as a particle ​

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Scattering

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​A device that uses light to manipulate images for purposes of study

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​An optical device is a piece of equipment that can divert the path of a light ray.

​Optical Device

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Multiple Choice

Optical devices that produce magnified images of distant objects by using a lens or a concave mirror to gather light.

• Microscope

• Telescope

• Mirror

• Laser

​Reflection occurs when light strikes a surface and its path is redirected backwards away from the surface.

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There are two types of reflection:

• specular reflection

• diffuse reflection

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​Optical Reflection

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​Specular reflection is the organized reflection of light off a very smooth surface, such as:

• a mirror

• a piece of polished metal

• the flat surface of a pond

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​Specular Diffusion

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Multiple Choice

When light reflects off of a completely smooth surface it is called:

• Diffuse Reflection

• Optical Reflection

• Smooth Reflection

• Specular Reflection

Diffuse reflection occurs when light strikes a rough surface.

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The reflected light scatters in all directions.

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​Diffuse Reflection

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Multiple Choice

The picture shows which type of reflection?

• Specular Reflection

• Optical Reflection

• Diffuse Reflection

• Scatter Reflection

​Bending of light

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​transition between mediums

​Refraction

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Multiple Choice

This diagram shows...

• specular reflection

• diffuse reflection

• total internal reflection

• refraction

Any material that light can pass through is called a medium.

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A medium can be described as transparent, translucent, and/or opaque.​

​ mediums of Refraction

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• ​reflection= mirrors

• refraction= ​lenses

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some devices use both reflection and refraction ​such as prisms

​Optic devices

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Multiple Choice

Which properties of light do optical technologies use?

• Reflection (bouncing of light)

• Rarefaction (bending of light)

• Both answers

• None of the answers

​Mirrors and lenses use reflection and refraction to divert light from an object and create an image.

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​Magnification

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​Light travels in straight lines.

Mirrors are optical devices that divert light using reflection.

• ​flat mirror (also called a plane mirror)

• convex mirror (bulges out at the middle) diverge light rays

• concave mirror (bows inward at the middle) converge light rays

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​Magnification Mirrors

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These 3 mirrors each have a different magnification.

Object height is the same for each mirror, but image heights are different​

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​Magnification Mirrors

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Multiple Choice

A makeup mirror that has a magnification of 2X produces an reflected image of a pimple with a height of 1 cm what is the actual size of the pimple?

• 1/2

• 1/4

• 2

• 4

Concave mirror light ray converge at the focal point​

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If the image is upright, then . . .

image height is positive ( + )

the magnification is positive ( + )

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​If the image is inverted, then . . .

image height is negative ( - )

the magnification is negative ( - )

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​Image Orientation Concave

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Multiple Choice

The man's image appears to be-

• upright

• inverted

• alive

• moving at a different rate

Ray Diagrams and the Law of Reflection

​Normal: an imaginary line drawn perpendicular to the reflecting surface where the light ray strikes it.

Angle of incidence: the angle between the incident ray and the normal, θi.

Angle of reflection: the angle between the reflected ray and the normal θr.

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Law of Reflection​

Multiple Choice

Law of reflection state that - The angle of incidence is .................. to the angle of reflection.

• equal
• double
• half

​A ray diagram shows the paths that light rays follow.

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Ray diagrams help explain shadow formation, and show how mirrors and lenses create images.

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Incident ray: the incoming light ray that strikes this mirror

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Reflected ray: the light ray that reflects off the surface of the mirror​

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Ray Diagrams

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Multiple Choice

The ray that bounces off the mirror is called the:

• Angle of Reflection

• Incident Ray

• Reflected Ray

• Angle of Incidence

​The law of reflection can be used to locate images in a flat mirror.

1. Draw incident rays from the object to the mirror.

2. Draw the reflected rays using the law of reflection.

3. Extend the reflected rays until they intersect behind the mirror at the location of the image.

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Ray Diagrams

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Apparent Image Reversal

the image appears to flip right and left sides

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In reality the image is inverted front to back ​