A Guide to Learning Optics Principles Educational Kit · A Guide to Learning Optics Principles...

Educational Kit

A Guide to

Learning Optics Principles

Using the

to Accompany

Darlene Burkhart, MA

Michael Larson, PhD

© Innovention Toys, LLC 2012. All rights reserved.

A Guide to Learning Optics Principles Using the Laser Game: Khet 2.0

Educational Kit

Table of Contents

Welcome! ............................................................................................................................................................ 1

Science Standards ............................................................................................................................................. 1

Goals ....................................................................................................................................................................... 2

Understandings ................................................................................................................................................. 2

Instructor Background Information .......................................................................................................... 2

What is Light? ...................................................................................................................................................................... 2

What is Light Reflection? ................................................................................................................................................ 3

What is Light Refraction? ............................................................................................................................................... 3

What is Light Diffraction? .............................................................................................................................................. 4

What Colors are in Light? ............................................................................................................................................... 4

What are Lasers? ................................................................................................................................................................ 4

How do Lasers Work? ............................................................................................................................................... 4

Instructional Strategies for a Sample Class Session with Learning Optics Principles

Using the Laser Game: Khet 2.0 (Introduction Class: 90 Minutes) ........................................... 6

Introduction/Pre-Assessment of Prior Knowledge Strategies ..................................................... 6

Safety Reminders to Students .................................................................................................................... 7

Student Exploration of Physics Labs ....................................................................................................... 7

Wrap-Up/Post-Assessment Strategies .............................................................................................................. 8


Using the Laser Game: Khet 2.0 (Extended Learning Option) ................................................ 8

Table of Contents (cont.)

Attachments ........................................................................................................................................................................... 9

Student Lab Worksheet/Khet 2.0 Optics Physics Lab 1: Bouncing Light (Reflection) .......10

Student Lab Worksheet/Khet 2.0 Optics Physics Lab 2: Bending Light (Refraction) .........12

Student Lab Worksheet/Khet 2.0 Optics Physics Lab 3: Splitting Light (Diffraction) ........14

Student Lab Worksheet/Khet 2.0 Optics Physics Lab 4: Filtering Light .................................16

Student Lab Worksheet/Khet 2.0 Optics Physics Lab 5: Exploring Laser Coherence ....... 18

Student Lab Worksheet Answers ........................................................................................................... 20

Assessment Strategy/ Light and Optics Focus Questions .............................................................22

Assessment Strategy/ KWLH Chart: Light and Optics ....................................................................23

Assessment Strategy/ Graphic Organizer: Light and Optics .........................................................24

Light and Optics Assessment (True/False Quiz) ..............................................................................25

Light and Optics Assessment (True/False Quiz) Answers ...........................................................26

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A Guide to

Learning Optics Principles

Using the Laser Game: Khet 2.0

Welcome!

Innovention Toys and Khet in Education are pleased to present Learning Optics

Principles Using the Laser Game: Khet 2.0. These physics labs present an activity-oriented

and inquiry-based approach that supports the introduction of the basic principles of light

and optics education. Exemplary science education provides for the development of

abilities necessary to do scientific inquiry and understandings about scientific inquiry

(National Science Education Standards/Content Standard A)1. We also know from effective

teaching practices that students construct deep meaning when provided the opportunity to

engage in inquiries where they question, formulate hypotheses, observe, investigate, and

communicate their results. This kit will take you and your students from identification of

prior knowledge through a hands-on process that includes questioning, guided

experimentation, group discussion and collaboration, and options for further research and

challenge. A quick assessment quiz comprised of true/false questions that can serve as a

pre- and post-assessment is also included. The Learning Optics Principles Using the Laser

Game: Khet 2.0 educational kit serves as a springboard into the cutting edge field of optics

and photonics. We welcome your students into this discovery adventure.

Science Standards

The National Science Education Standards (1996) state that "all students should

[understand that] light travels in a straight line until it strikes an object. Light can be

reflected by a mirror, refracted by a lens, or absorbed by the object" (p. 127). Students

should also understand that "light interacts with matter by transmission (including

refraction), absorption, or scattering (including reflection). To see an object, light from that

object— emitted by or scattered from it—must enter the eye" (p. 155).1

1 National Research Council. "Front Matter." National Science Education Standards.

Washington, DC: The National Academies Press, 1996. 1. Print.

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Goals

To introduce students to basic optics principles, including an understanding of and

ability to explain:

The law of reflection (the angle of incidence equals the angle of reflection)

The physics of light refraction, light diffraction, light filtering

The basic principles of how lasers work and how they are used

Understandings

Light entering a mirror creates an angle of incidence. When light bounces off, or exits, it creates an angle of reflection. The angle of incidence equals the angle of reflection.

Light bends, or refracts, when it passes from one transparent medium into another. White light has all the colors of the rainbow. (A rainbow can be split into many colors.) White light can be split or separated into many colors using a diffraction grating or prism. A filter allows only its own color to pass through it. Concave lenses curve outward; convex lenses curve inward. Concave lenses spread entering light into a wider beam; convex lenses narrow

entering light to a point. Laser light has several properties: They are monochromatic (produce only one color), exhibit coherence and emit a single wavelength of light in phase.

Instructor Background Information

What is Light?

What exactly is light and how do we see? This is a question that has been pondered

over centuries resulting in a changing definition. A Greek engineer named Hero (10 – 70

A.D.) thought that our eyes sent out “feelers” (like antenna) to detect the things we see. He

also thought that light traveled at an infinite speed. Then an Arabian physicist, Alhazen

(965 – 1039 A.D.), developed the theory that light has a source, travels from that source to

objects, and reflects off the objects to our eyes. His thinking has served as a basis for much

of our current thought about light.

Scientists continued to investigate light and two theories emerged. Some scientists

believed that light was a stream of tiny particles that traveled in straight lines. Sounds

logical, doesn’t it? Other scientists thought that light consisted of waves, similar to those

easily observable in the ocean. Through much observation and investigation, scientists now

embrace both lines of thought and believe that light has both particle and wave behavior.

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Light can be manipulated. It can bounce, bend, split, and scatter. The study of the

behavior of light and the accumulation of knowledge scientists have collected is called the

science of optics. The practical application of light and optics is photonics. Photonics is a

science-based technology that develops applications in various industries, such as

telecommunications, information technology, entertainment, precision manufacturing,

biology and medicine, homeland security and defense, astronomy, aerospace, and others.

What is Light Reflection?

If you are playing basketball and bounce a ball to another player, the ball will hit the

smooth gym floor and rebound in roughly the same angle, as long as a spin hasn’t been

applied to it! It’s the same with light. If light strikes a smooth surface, it will bounce off at an

angle equal to the one at which it first hit the mirror. This is called the law of reflection. In

optics and physics terms, this law is stated as “the angle of incidence equals the angle of

reflection.”

Of course, our world consists of smooth and rough surfaces. When light strikes a

smooth surface and bounces off at an equal angle, as we just discussed, this is called

specular reflection. When light strikes a rough or uneven surface, the light rays reflect off

at all sorts of angles because of the uneven surface. This is called diffuse reflection. Diffuse

reflection can be quite useful, enabling us to see objects from all directions.

What is Light Refraction?

When light crosses a surface at an angle, such as from air into glass or from glass

back into air, the light rays speed up or slow down, and they bend. When light bends, we

call this refraction. Beams that are directly perpendicular to a surface don’t bend, and a

line perpendicular to a surface is called the normal.

A lens is a piece of glass that has curved sides. The curved sides refract light as it

enters, then exits the lens. If the lens is convex (thicker in the middle), the light rays will

come together, or converge, as they exit. If the lens is concave (thinner in the middle), the

light rays will spread apart, or diverge, as they exit. A convex lens can focus light and

project an image at a point we call the focal point. The distance from a lens to its focal

point is called the focal length.

Lenses are extremely useful in many photonics applications. Some of these basic

uses include binoculars, telescopes, cameras, microscopes, projectors, magnifying glasses,

and eyeglasses.

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What is Light Diffraction?

Diffraction action uses diffraction gratings to look at various types of lights. A

diffraction grating acts like a prism, spreading visible light into its component colors. The

light that you see from a light source is the sum of all these colors. Each color corresponds

to a different frequency of light. The diffraction grating sorts light by frequency, with violet

light (the highest frequency of visible light) at one end of the spectrum and red light (the

lowest frequency of visible light) at the other.

What Colors are in Light?

By using color filters, we can observe exactly which colors can pass through a filter

and which colors cannot. For example, when white light shines through a red filter, the

orange, yellow, green, blue, and violet components are absorbed by the filter. Only the red

light can pass through. In the Khet 2.0 Physics Lab 3, students will be able to observe for

themselves that one of the characteristics of most laser light is that it is monochromatic,

consisting of only one color.

What are Lasers?

The definition of a laser as it appears on dictionary.com is “a device that produces a

nearly parallel, usually monochromatic, and coherent beam of light by exciting atoms to a

higher energy level and causing them to radiate their energy in phase.”2 Translation? A

laser is basically a light that usually consists of a single color. It has other characteristics, as

well. A laser produces a focused light that can shine for long distances without spreading (it

is coherent). The photons (light) are also emitted with the same wavelength and are “in

step” with the previous photons that have been emitted. This light carries lots of energy,

hence, the intensity of the laser beam.

How do Lasers work?

The name LASER stands for Light Amplication by Stimulated Emission of Radiation.

A laser is a tube or rod that has a gas or a mixture of gasses in it (for example, helium,

neon), a crystal (for example, a ruby), or a liquid. There are mirrors on each end of the tube

and a power source. When the power is turned on, the atoms in the gas, crystal, or liquid

become stimulated (excited with energy). These atoms then lose their extra energy by

giving off light, which bounces back and forth between the mirrors. The atoms that have

already given off light get excited again and give off more light energy. Inside the

2 "laser." Dictionary.com. 2012. http://dictionary.reference.com/browse/laser (2 February 2012).

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tube, the light keeps getting stronger. One mirror allows some of the light to pass through

it, and when it emerges, it is extremely intense. It is also all one wavelength and doesn’t

spread out much as it travels over a long distance (it is coherent).

Because different sources or media within a laser (i.e. gas, crystal, liquid) give off

light of different wavelengths, one laser might give off red light, another green, etc.

N.B. As students further research lasers, they may discover that there are some lasers

which are not single spatial mode and, consequently, they emit a broad spectrum of light,

or emit different wavelengths simultaneously. These lasers retain their classification as

“lasers” because of their method of producing light through stimulated emission.

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Using the Laser Game: Khet 2.0 (Introduction Class: 90 Minutes)

I. Introduction/Pre-Assessment of Prior Knowledge Strategies

When beginning a class or introducing a new topic, it is helpful for the instructor to

establish a baseline of what students know about, in this case, basic optics principles and

lasers. This will be useful as the class progresses through an initial discussion. Choose any

one of the following options, or substitute an alternative choice as a pre-assessment.

1. Light and Optics Focus Questions (for class discussion)

What is light?

How does light behave?

What happens when light hits an object?

What is white light?

What is a laser?

What is the science of optics? …the science of photonics?

Why is it important to understand light and lasers?

N.B. This isn’t the time to engage in a lengthy or detailed explanation; rather, the

purpose is to gain an understanding of what students know so that the instructor can

provide them with enough information to move them forward into the Khet 2.0 Physics

Labs. (See the “Light and Optics Focus Questions” sample in Attachments, page 22)

2. Classroom Demonstration

Demonstrate use of a laser, periscope, binoculars, hand-held microscope, etc.

(Scientific toys and gadgets always capture attention!) Again, ask a few probing questions.

3. KWLH Chart: Light and Optics

Use this type of chart to guide questioning and to help students assess what they

know about a topic. The letters stand for what students know (K), want to know (W), and

have learned (L). In addition, this chart helps students to articulate plans for further

learning. KWLH charts can be used before, during, and after learning experiences as both

formative and summative assessments. (See the “KWLH Chart: Light and Optics” sample in

Attachments, page 23)

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4. Graphics Organizer: Light and Optics

Use the Graphics Organizer: Light and Optics as a springboard for discussion. The

instructor may choose whether or not to list student responses for later discussion as a

post-assessment option. (See the “Graphics Organizer: Light and Optics” sample in

Attachments, page 24)

5. Light and Optics Assessment Quiz (True/False)

This option provides for a quantifiable approach to comparing students’ prior

knowledge to knowledge gained after using the Khet 2.0 Physics Labs. (See the “Light and

Optics Assessment Quiz” sample in Attachments, page 25)

II. Safety Reminders to Students

The lasers in the Laser Khet 2.0 Game are authentic, working diode lasers. Remind

students to be careful that they do not stare into the lasers, nor direct or use the lasers in

any way that might cause them to shine into their own or another student’s eyes.

III. Student Exploration of Physics Labs

The instructor can help students form groups (one group for each lab/template), set

expectations for participation, and provide a brief explanation of the labs, if needed.

Otherwise, this is a time for the students to explore. Instructions (Steps to Do) and Inquiry

Questions for the labs are provided both on the lab templates and the student lab activity

sheets (see attachments for student lab activity sheets). Depending on the amount of

available instructional time, the instructor may have the students orally discuss answers or

write them on the student lab activity sheets for later discussion. It’s time for student

investigation! Rotate student groups as time allows.

Physics Labs:

I. Khet 2.0 Optics Physics Lab 1: Bouncing Light (Reflection)

II. Khet 2.0 Optics Physics Lab 2: Bending Light (Refraction)

III. Khet 2.0 Optics Physics Lab 3: Splitting Light (Diffraction)

IV. Khet 2.0 Optics Physics Lab 4: Filtering Light

V. Khet 2.0 Optics Physics Lab 5: Exploring Laser Coherence (optional lab, if

time allows)

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IV. Wrap-Up/Post-Assessment Strategies

The instructor’s post-assessment option choice might be a continuation of the pre-

assessment choice, but can easily vary. For example, if the instructor chooses the KWLH

Chart, he/she may wish to complete the first two columns as the pre-assessment option

and follow-up with the last two columns as a post-assessment option…or the instructor

may choose to use the Light and Optics Focus Questions or the Graphic Organizer activity

for a pre-assessment, then follow-up with the Light and Optics Assessment Quiz as a post-

assessment choice. The Assessment Quiz offers a quantifiable/formal method of

assessment while the other choices offer informal methods of assessment. Whatever the

assessment choice, the idea is simply to measure and show student growth, and if

extending the unit, to guide planning for future instructional goals.

Instructional Strategies for a Sample Class Sessions with Learning Optics Principles

Using the Laser Game: Khet 2.0 (Extended Learning Option)

If additional time is available, the instructor may wish to cover these principles with

more depth. Here are some suggestions for extending learning options by modifying the

sequence and complexity of the Instructional Strategies listed above:

Extend the Introduction/Pre-Assessment Strategy choice by adding to the depth of

the probing questions asked. Allow time for follow-up discussion and exploration on

strands that students have introduced into the conversation.

Add the Khet 2.0 Optics Principles Physics Lab 5 into the rotation.

Allow additional time for selected Super Challenge Options. The Super Challenge

Options can be done individually or in small groups.

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Attachments

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BOUNCING LIGHT (REFLECTION)

Khet 2.0 Optics principles Physics lab 1

Name:

Essential Question: How might the reflection of light be used in real life applications?

Vocabulary

Angle of incidence Invisible light (challenge)

Angle of reflection Infrared radiation (challenge)

Incident beam Specular reflection (challenge)

Reflected beam Diffuse reflection (challenge)

Perpendicular

Experiment! Steps to Do

Place the Sphinx laser source into the corner spot as indicated.

Place one pyramid piece in the recessed square in front of the laser, making sure the mirrored surface is oriented as indicated.

Place one pyramid piece in the blue square drawn near the center of the board, again making sure the mirrored surface is oriented as indicated.

Place the observation wall along the bottom edge as indicated. Fire the Sphinx laser and observe where the reflected laser beam hits the

wall. (Answer Question 1)

Rotate the pyramid piece 15 degrees clockwise so its corners align with the orange marks.

Fire the Sphinx laser and observe where the reflected laser beam hits the wall. (Answer Question 2)

Rotate the pyramid piece an additional 15 degrees clockwise so its corners align with the green marks.

Fire the Sphinx laser and observe where the reflected laser beam hits the wall. (Answer Questions 3 and 4)

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Inquiry Questions

1. Pyramid Position: Blue Square When the angle between the beam and the perpendicular (the normal) to the mirror is 45 degrees, what is the angle between the incident beam and the reflected beam?

2. Pyramid Position: Orange Square When the angle between the beam and the perpendicular (the normal) to the mirror is 60 degrees, what is the angle between the incident beam and the reflected beam? 3. Pyramid Position: Green Square When the angle between the beam and the perpendicular (the normal) to the mirror is 75 degrees, what is the angle between the incident beam and the reflected beam?

4. What conclusions about angles of incidence and angles of reflection can be drawn from these observations?

Super Challenge Options

Compare and contrast specular light with diffuse light. Use a Venn Diagram to show your findings. Use what you discovered in this lab as you research specular reflection to find out how light angles are used in real life applications. Research the use of invisible light (infrared radiation) in real life applications. Create a demonstration to share your findings.

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BENDING LIGHT (REFRACTION)


Name:

Essential Question: How might the bending of light be used in real life applications?

Vocabulary

Convex lens

Concave lens

Focal point

Fraction

Index of refraction (challenge option)


Place the Sphinx laser source into the corner spot as indicated.

Place the Khet pyramid piece and the two Eye of Horus beam splitters in the

indicated spots.

Place the observation wall along the dashed line and the convex lens in the

designated spot.

Fire the Sphinx laser to create three beams entering the convex lens. While

pressing the laser, move the observation wall closer to, then farther from the

lens. Observe where the three beams hit the wall.

(Answer Question 1)

Remove the convex lens and place the concave lens in the designated spot.

While pressing the Sphinx laser as before, move the observation wall closer

to, then farther from the lens. Observe where the three beams hit the wall.

(Answer Question 2)

Place the convex lens back in its designated spot, next to the concave lens.

While pressing the Sphinx laser as before, move the observation wall closer

to, then farther from the lens. Observe where the three beams hit the wall.

(Answer Questions 3 and 4)

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Inquiry Questions

1. After firing three parallel beams through the convex lens, how do the three laser

spots on the observation wall move as you slide the wall closer to and farther from

the lens? Is there a place where the spots cross?

2. After firing three parallel beams through the concave lens, how do the three laser

spots on the observation wall move as you slide the wall closer to and farther from

the lens? Is there a place where the spots cross?

3. After firing three parallel beams through the convex and concave lens

combination, how do the three laser spots on the observation wall move as you slide

the wall closer to and farther from the lens? Is there a place where the spots cross?

4. What conclusions about the way light travels through lenses can be drawn from

these observations?


Research the way bending light is used in a device; i.e. magnifying glass, projector,

telescope, microscope, eye glasses, etc.

Draw a diagram showing how a device that uses light refraction works. Share your

work. ...or research and demonstrate materials’ “index of refraction.”

With a friend, brainstorm and design a new device that uses the bending of light to

benefit mankind.

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SPLITTING LIGHT (DIFFRACTION)


Name:

Essential Questions: How does the use of light diffraction affect our everyday lives? How might scientific knowledge be shared with others?

Vocabulary

Diffraction

Diffraction grating slide

ROYGBIV


Place the flashlight in the indicated spot. Place the diffraction grating slide in the holder at the indicated spot. Place the observation wall at the indicated spot. Turn on the flashlight and observe the colors on the observation wall.

(Answer Question 1) Remove the flashlight from the board. Place the Sphinx laser source in the corner spot as indicated. Place the pyramid piece in the recessed square in front of the laser, orienting

the mirror as indicated. Fire the Sphinx laser and observe the red light only on the observation side

wall. (Answer Questions 2 and 3)

Inquiry Questions

1. What do you see when the flashlight beam passes through the diffraction grating? Draw a conclusion about what happens when light passes through a diffraction grating slide. 2. What do you see when the laser beam passes through the diffraction grating slide? Draw a conclusion about why your observations for light from a flashlight and the beam from a laser are different as they travel through the diffraction grating slide.

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Inquiry Questions (cont.)

3. Think about where you saw the color red when the flashlight was shone through the diffraction grating slide. Think about where you saw the color red when the laser beam was fired through the diffraction grating slide. How do these locations compare? Why do you think this is so?


Using text or online sources, research to find out how diffraction gratings are designed and produced. What devices have diffraction gratings? Do diffraction gratings also appear in nature? If yes, where? Using bubble solution, two pieces of acetate paper, or other material, create a demonstration to share that shows the diffraction of light…or prepare a collection of at least three items that demonstrate light diffraction.

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FILTERING LIGHT


Name:

Essential Questions: How do filters help us to understand the composition of various forms of light? How might these various forms be used in the future?

Vocabulary

Filter Laser light (challenge)

Opaque Visible spectrum (challenge)

Transparent Wavelength (challenge)

White light


Place the pyramid piece (notice the orientation), the flashlight, the filter holder, the Sphinx laser source, and observation wall as indicated onto the Khet board.

Put the red filter slide (in a vertical position) into the slide holder. Turn on the flashlight and observe the color projected onto the observation

wall. Replace the red filter with the blue filter. Again, observe the color projected

onto the wall. Replace the blue filter with the green filter. Again, observe the color projected

onto the wall. (Answer Question 1)

Remove the flashlight from the Khet board and replace the green filter with the red filter.

Fire the Sphinx laser and observe the color projected onto the observation wall.

Repeat using the blue filter, and then using the green filter. Observe the color projected onto the observation wall. (Answer Questions 2 and 3)

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Inquiry Questions

1. What do you see on the observation wall when the flashlight beam shines through the red, blue, and green filters? Draw a conclusion about what happens when white light passes through a series of colored filters.

2. What do you see when the laser beam passes through the red, blue, and green filters? Draw a conclusion about what happens when laser light passes through a series of colored filters. 3. Why do you think your observations for Question 1 and Question 2 were different?


Research the differences between the invisible and visible light. What changes over the spectrum? What categories of light are found on the spectrum? What different applications are found within each category? Can you find evidence of research and innovation that is happening within any of the categories? Please explain. Predict where future light/photonics innovations might next happen.

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EXPLORING LASER COHERENCE


Name:

Essential Questions: How has the discovery of lasers impact the lives of mankind? How might this knowledge be applied in the future?

Vocabulary

Laser light

Coherence

Wavelength, medium, diode, photons, phase, electrons (challenge)

Stimulated emission (challenge)

Experiment! Steps to Do and Inquiry Questions

1. Make a prediction about how far you can see the laser light shine when the Sphinx laser source is fired. My prediction:

2. Test your prediction and measure your results. How do your results compare

with your prediction?

3. Under what conditions might you be able to see farther when firing the Sphinx laser?

4. Set up a laser path on your Khet board using the Sphinx laser and the

pyramids. Fire the Sphinx laser. How many pieces can be part of the path before you lose alignment?

5. What might cause this lost alignment?

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Experiment! Steps to Do and Inquiry Questions (cont.)

6. Try setting up a laser light path using a Sphinx laser source and several

pyramid pieces on desks within your classroom, or out in the hall if your instructor agrees. Place the pieces at least five feet apart. Fire your laser. Reposition pieces to improve your alignment. How many turns (angles) are you able to achieve?

7. Draw a conclusion about your Sphinx laser light’s coherence based on your

observations.


Research to find out the following: What does the acronym “LASER” stand for? For what purpose and when was the first laser invented/used? How do lasers work? Draw a diagram showing a laser’s essential parts. (Seek a source other than the clip art on this Physics Lab sheet.) In what ways are lasers used today? Make a prediction as to how you think lasers might be used in the future. Defend your prediction with facts from your research.

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Answers for Khet 2.0 Physics Lab Student Sheets

Khet 2.0 Optics principles Physics lab 1: BOUNCING LIGHT (REFLECTION)

1. The angle between the incident beam and the reflected beam is 90 degrees, a right angle.

2. The angle between the incident beam and the reflected beam is 120 degrees, twice the

incident angle.

3. The angle between the incident beam and the reflected beam is 150 degrees, twice the

incident angle.

4. The angle of incidence equals the angle of reflection.

Khet 2.0 Optics principles Physics lab 2: BENDING LIGHT (REFRACTION)

1. As the wall moves closer to the lens from the focal point, the spots move apart. As the wall

moves farther from the lens from the focal point, the spots also move apart. There is a place

where the beams cross; the distance from that point to the lens is called the “focal point” of

the lens.

2. As the wall moves closer to the lens, the spots move closer together. As the wall moves

farther from the lens, the spots move apart. There isn’t a place where the beams cross.

3. The three spots stay about the same distance apart no matter where the wall is placed.

4. Convex lenses bring light rays together (converge) and concave lenses spread light rays

apart (diverge.)

Khet 2.0 Optics principles Physics lab 3: SPLITTING LIGHT (DIFFRACTION)

1. A rainbow of colors should be seen. This is because the diffraction grating splits white light

from the flashlight into separate colors, ROYGBIV (red, orange, yellow, green, blue, indigo,

violet)

2. A red light from the laser beam should be seen. This conclusion could be drawn because

white light is composed of all the colors while laser light is composed of only one color; in

this case, red.

3. The red spots appear at the same places, since red light is bent, or diffracted by the same

amount whether it comes from a laser or a flashlight.

Khet 2.0 Optics principles Physics lab 4: FILTERING LIGHT

1. You will be able to see that the light that passes through the filters and hits the wall matches

the filter colors. A red beam can pass though the red filter, a blue beam can pass through the

blue filter, and a green beam can pass through the green filter. Your conclusion will depend

on what color filters the white light is passing through. For example: can white light go

through two filters that are different colors? Draw another conclusion in answer to this

question and test it.

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2. The red laser beam passes through the red filter. The red laser beam cannot pass through

the green and blue filters. Red laser light can only pass through the red filter because it is

red. The green and blue filters block the red laser light.

3. The observations for Questions 1 and 2 were different because we were observing white

light in Question 1 and red laser light in Question 2. Colored filters only allow their own

color to pass through them; they absorb the other colors. Therefore, it seems logical to

conclude that laser light is only one color; in this case, red.

Khet 2.0 Optics principles Physics lab 5: EXPLORING LASER COHERENCE

1. – 6. Answers will vary.

7. With laser light, coherence refers to the intensity, focus, and extremely low

dispersion (spreading) of the beam.

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Light and Optics Focus Questions

What do you know about light and optics?

What is light?

How does light behave?

What happens when light hits an object?

What is white light?

What is the science of optics?

What is a laser?

What is the science of photonics?

Why is it important to understand light and

lasers?

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KWLH Chart: Light and Optics

What Do You

Know about Light and

Optics?

What Do You

Want to Know about Light and Optics?

What Have You

Learned about Light and

Optics?

How Can You Learn More?

What new questions do you have? Where will you research to gain further information? What can you read and do to learn more on this topic?

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Graphic Organizer: Light and Optics

What is light?

What is the science of optics?

What is light

reflection?

What is light

refraction?

What is light

diffraction?

How/why is light

filtered?

What are lasers?

What is the science of photonics?

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Light and Optics Assessment Quiz (True/False) Name:

Circle the correct answer for each item.

1 White light has all the colors of the rainbow in it. T F

2 A rainbow is made up of many colors. T F

3 A laser beam is made up of many colors. T F

4 A diffraction grating or prism separates the colors in a white beam. T F

5 A filter that is red will only let red light pass through it. T F

6 A filter that is blue will let all colors pass through it except for blue. T F

7 A laser beam has only one color in it. T F

8 The light from a flashlight passing through a green filter will be green. T F

9 The light from a red laser passing through a green filter will be red. T F

10 A concave lens is curved inward. T F

11 A convex lens is curved inward. T F

12 When light enters a concave lens it spreads the light into a wider beam. T F

13 When light enters a convex lens it narrows the light to a POINT. T F

14 When a light beam enters at the middle of either a concave or convex lens, it will exit the middle of the lens without bending.

T F

15 When light is reflected off a mirror at an angle, the angle created by the light entering the mirror is called the angle of reflection.

T F

16 When light is reflected off a mirror at an angle, the angle created by the light exiting the mirror is called the angle of reflection.

T F

17 For a light beam hitting a mirror, the angle of incidence is equal to the angle of reflection.

T F

18 When light is reflected off a mirror as shown in the picture, the angle of incidence is 30 degrees.

T F

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Light and Optics Assessment Quiz (True/False) Answers Name: ANSWER KEY

1 White light has all the colors of the rainbow in it. T

2 A rainbow is made up of many colors. T

3 A laser beam is made up of many colors. F

4 A diffraction grating or prism separates the colors in a white beam. T

5 A filter that is red will only let red light pass through it. T

6 A filter that is blue will let all colors pass through it except for blue. F

7 A laser beam has only one color in it. T

8 The light from a flashlight passing through a green filter will be green. T

9 The light from a red laser passing through a green filter will be red. F

10 A concave lens is curved inward. T

11 A convex lens is curved inward. F

12 When light enters a concave lens it spreads the light into a wider beam. T

13 When light enters a convex lens it narrows the light to a POINT. T

14 When a light beam enters at the middle of either a concave or convex lens, it will exit the middle of the lens without bending.

T

15 When light is reflected off a mirror at an angle, the angle created by the light entering the mirror is called the angle of reflection.

F

16 When light is reflected off a mirror at an angle, the angle created by the light exiting the mirror is called the angle of reflection.

T

17 For a light beam hitting a mirror, the angle of incidence is equal to the angle of reflection.

T

18 When light is reflected off a mirror as shown in the picture, the angle of incidence is 30 degrees.

F

A Guide to Learning Optics Principles Educational Kit · A Guide to Learning Optics Principles...

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