Laser

Question 1

LASER

Answer 1

Light amplification by stimulated emission radiation

Question 2

New global system classes

Answer 2

1
1M
2
2M
3R
3B
4

Question 3

NOHD

Answer 3

Nominal ocular hazard distance

Question 4

EOHD

Answer 4

Extended ocular hazard distance

Question 5

Effects of Laser

Answer 5

Skin/ tissue damage
Eye damage
Other[fire,poisonous,]

Question 6

Explain Laser Energy

Answer 6

Monochromotic 1 colour same wavelength in phase

Question 7

Output

Answer 7

1W =1000mW
1J = 1000mJ

Question 8

Wavelength

Answer 8

1000000000nm =1m

Question 9

Divergence

Answer 9

1mr = 1000radians
1° = 17.5932529

Question 10

Permanent eye damage can be a result of

Answer 10

Direct illumination of the eye
Indirect illumination [reflected]

Question 11

Types of reflection

Answer 11

Diffuse - objects that reflect in many directions
Specular - mirror like objects reflect in one direction[most dangerous]

Question 12

MPE

Answer 12

Maximum permissible exposure [ maximum dosage of radiation considered to be safe from causing permanent eye damage

Question 13

MPE depends on 2 things

Answer 13

Laser wavelength
Exposure time

Question 14

Laser light vs normal light

Answer 14

NL non coherent light where waves are not in phase- beam spreads
LL coherent light where waves are in phase beam much more directed

Question 15

Skin damage typesx2

Answer 15

Thermal - or burn tissue is heated to the point denaturation of protien occurs
Photochemical- light triggers chemical reactions in the tissue

Question 16

Laser classification

Answer 16

American & new global system

Question 17

1M

Answer 17

Safe for unaided viewing but may be hazardous if collecting optics are employed within the beam
-LRF

Question 18

2M

Answer 18

Same ocular hazard as 2 may be hazardous if collecting optics are employed within the beam
-Laser pointers

Question 19

3R

Answer 19

Potentially hazardous but the probability of injury is small.
Not capable of causing skin damage
Cannot produce hazardous diffuse reflection
Blinking reflex can protect if lasers visible
Laser pointers

Question 20

NOHD formula

Answer 20

=MPE-distance+risk assessment + operative considerations

Question 21

EOHD

Answer 21

Extended optical hazard distance

Question 22

EOHD safe distance depends on x3

Answer 22

Diameter of lens
Magnification of optics
Loss of energy in lenses

Question 23

Laser areas of use

Answer 23

Commercial
Industrial
Medical
Military
Scientific

Question 24

1

Answer 24

Not hazardous under reasonably forsewable conditions even if the beam is viewed with up to and including 50mm collecting optics
-Cd players

Question 25

2

Answer 25

Limited to the visible part of the ems 400-700nm where protection is afforded by the blinking reflex to bright light including upto 50mm collecting optics
Prolonged staring can be harmful especially shorter wavelengths
Laser pointers

Question 26

3B

Answer 26

Are hazardous but viewing diffuse reflections are typically safe
Probability of skin injury unlikely
Laser pointers

Question 27

4

Answer 27

Most hazardous &capable of causing damage to eye and skin
May produce hazardouse diffuse reflections, ignite flammable materials and produce airborne contaminants
Laser designators

Question 28

OD

Answer 28

Optical density
Defined as logarithmic
Googles ability to protect

Question 29

Laser class depends on 2 things

Answer 29

Effect
Wavelength