PASCO AP-8586 User Manual

Instruction Manual

Manual No. 012-08088A

Laser

Speed of Light

Apparatus

Model No. AP-8586

Apparatus Model No. AP-8586

Table of Contents

Equipment List........................................................ 3-4

Introduction ............................................................. 5

Equipment Setup ..................................................... 5-7

Suggested Experiments ............................................. 7-10

Sample Data............................................................ 11

Appendix A: Specifications............................................ 12

Appendix B: Plotting Data in DataStudio............................. 13

Appendix C: Laser Safety............................................. 14

Appendix D: Technical Support ....................................... 16

Appendix E: Copyright and Warranty Information .................. 17

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Model No. AP-8586 Laser Speed of Light System

Laser Speed of Light System

Model No. AP-8586

Equipment List

DIODE LASER FOR

OS-8528

OPTICS SYSTEMS

1

D

I
O

D

E

L

0
0

3

A

­0

S

6

1

E

5

R

7

A
V

L

O

A

I

S

D

E

E

R

F

X

R

L

P

O

IG

O

M

S

H

U

T

T

R

H

IS

E
I
S

E

A

M

P

IT

E

T

R

E

T

D

U

R

E

2

3

4

5

Metrologic®

45-725
Receiver
DATE 0400
9V

6

7

8

9 10

Included Equipment Replacement

Model Number*

1. Diode Laser with power adapter (1)

2. Component Carrier (2)

3. Lens, +127 mm (1)

4. Laser Alignment Bench (1)

5. Light Receiver (1)

6. Stainless steel pads (4)

7. Cable, coaxial, RCA male to BNC male (1)

8. Cable, coaxial, 3.5 mm phone plug to BNC male (1)

OS-8528A

OS-9107

OS-9134

OS-9172

†See note

OS-9148

†See note

†See note

9. Cable, coaxial, BNC to male (1)

10. Concave Mirror Assembly (1)

*Use Replacement Model Numbers to expedite replacement orders.

†

Contact Pasco for replacement of items (see page 15 for contact information).

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†See note

003-02226

3

Laser Speed of Light System Model No. AP-8586

Equipment List (Continued)

Additional Equipment Required (for experiments) Replacement

Model Number*

Function Generator, wide range

Oscilloscope, 60 MHz

Tripod

Tape measure

Tape (for marking floor)

Plumb bob (for indicating mirror position)

Laser Safety Goggles or protective shields (recommended, but
not required)

**

SB-9549A

NA

NA

SE-8172A

NA

NA

NA

NA = not available from PASCO scientific

** See Appendix C: Laser Safety for more information about safety goggles.

About the Equipment:

Diode Laser - The diode laser emits an intense, narrowly-focused beam of light. In this

experiment, the diode laser is powered by a function generator, which modulates the light
intensity at approximately 3 MHz. The laser is equipped with adjustment screws for
precisely aiming the light at the mirror.

Concave mirror - The concave surface of the mirror helps to focus the light as it is
reflected. The mirror is also equipped with adjustment screws for aiming the light back to the
receiver.

Light Receiver - The receiver is designed for receiving audio and video signals transmitted
via modulated light. Since the light receiver is sensitive to very high-frequency modulation,
it is ideally suited to the experiment in this manual. There are two sensitive elements on the
receiver; in this experiment, you will use only the one labeled “Video.”

+127 mm Lens - The lens is used to focus the light onto the sensitive element of the
receiver.

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Model No. AP-8586 Laser Speed of Light System

s

d

Introduction

The velocity of light in free space is an important and intriguing
constant of nature. Whether the light comes from a laser on a desktop
or from a star that is hurling away at fantastic speeds, the velocity of
light will yield the same constant value. In more precise terminology,
the velocity of light is independent of the relative velocities of the light
source and the observer.

As Einstein first presented in his Special Theory of Relativity, the
speed of light is critically important in some surprising ways:

1. The velocity of light establishes an upper limit to the velocity that

may be imparted to any object.

2. Objects moving near the velocity of light follow a set of physical

laws drastically different, not only from Newton’s Laws, but from
the basic assumptions of human intuition.

It is not surprising that a great deal of time and effort has been invested
in measuring the speed of light. Some of the most accurate
measurements were made by Albert Michelson between 1926 and

1929. Michelson measured the velocity of light in air to be 2.99712 x

8

m/sec. From this result, he deduced the velocity in free space to be

10

2.99796 x 108 m/sec.

Equipment Setup

1. Stick four stainless steel strips to the front of the
receiver (Figure 1).

2. Mount the laser on its L-shaped bracket, with the
bracket bent away from the laser (Figure 2).

DIODE LASER FOR

OS-8528

OPTICS SYSTEMS

DIODE LASER

003-06157

AVOID EXPOSURE
LASER LIGHT IS EMITTED
FROM THIS APERTURE

Figure 2: Laser with bracket

Figure 1:
Receiver

WARNING: Before
setting up your equipment,
please inform your student
of the hazards of lasers an
enforce appropriate safety
precautions in your
classroom. For more
information, see Appendix
C: Laser Safety in this
manual.

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