LASERS CERTIFICATION EXAM
_________ reported in 1965 that a ruby laser could vaporize enamel. - Correct answer-
Stern and Sognnaes
First pulsed Nd:YAG laser released in ______ and cuts ______ tissue. - Correct
answer-1990, soft tissue
In _____ the first dental hard tissue was FDA cleared and is called _______. And the
______ laser a year later. - Correct answer-1997
Er: YAG laser
Er, Cr: YSGG
The word LASER is an acronym standing for _________. - Correct answer-Light
Amplification by Stimulated Emission of Radiation
Theorized the concept of stimulated emission - Correct answer-Einstein
Theorized that an excited electron will spontaneously return to its ground state - Correct
answer-Bohr
First ruby laser was created in _____ by ______. - Correct answer-1960, Ted Maiman
Laser parameters include what 3 things? - Correct answer-1)Duration of exposure
2)Fiber Diameter
3)Wavelength
Lasers are:
______chromatic?
_____directional?
coherent or noncoherent?
emitted from a stimulated ____________. - Correct answer-monochromatic: made of a
single wavelength (visible or infrared)
unidirectional
coherent (all peaks and valleys of each wave travel in unison)
active medium
What states can the active medium be in? - Correct answer-solid, gas, semiconductor
What type of active medium is used in Er: YAG? - Correct answer-solid state using
crystal matrix (erbium laced yttrium, aluminum and garnet)
, What type of gas is used when the active medium is sealed in an air tight chamber? -
Correct answer-CO2
Diode lasers have what type of active medium? - Correct answer-semiconductor
what photons form the laser? - Correct answer-light that leaks from the output coupler
Stimulated emission: - Correct answer-atoms of the active medium are stimulated to a
higher energy level--> released as a photon as the atom returns to a more stable lower
energy level.
Amplification - Correct answer-Released photons can go on to stimulate more atoms in
the crystal, thus producing more photons
Energy density depends on what 3 things? - Correct answer-energy, divergence
(tendency of a laser beam to spread outward=laser beam diameter increases), and
distance
Energy is measured in ______ - Correct answer-Joules (millijoules)
Power is ______ and is measured in _______ - Correct answer-rate of doing work, or
energy used over a period of time and is measured in Watts (J/sec)
Frequency is measured in _____. - Correct answer-Hertz ( laser pulses/sec)
What is the most important variable dictating how the laser beam will interact with the
target tissue? - Correct answer-Peak Power
Define Peak Power: - Correct answer-power level in each individual laser pulse,
however it is not visible to the operator
Describe Peak Power in the 3 types:
1) Continuous
2) Gated
3) Free running pulsed - Correct answer-1) the peak power equals the average power
displayed
2) Average power is half of peak power
3) Low Average power, very high peak power
What are the two basic forms of pulsed laser modes? - Correct answer-Gated wave
Free running pulsed
How is the gated wave pulse created? - Correct answer-created with a shutter that
blocks the laser beam from reaching the handpiece and target tissue at varying speeds:
the laser is on constantly but the shutter device blocks the light from transmitting.
(example: flashlight moving hand in front of it)
_________ reported in 1965 that a ruby laser could vaporize enamel. - Correct answer-
Stern and Sognnaes
First pulsed Nd:YAG laser released in ______ and cuts ______ tissue. - Correct
answer-1990, soft tissue
In _____ the first dental hard tissue was FDA cleared and is called _______. And the
______ laser a year later. - Correct answer-1997
Er: YAG laser
Er, Cr: YSGG
The word LASER is an acronym standing for _________. - Correct answer-Light
Amplification by Stimulated Emission of Radiation
Theorized the concept of stimulated emission - Correct answer-Einstein
Theorized that an excited electron will spontaneously return to its ground state - Correct
answer-Bohr
First ruby laser was created in _____ by ______. - Correct answer-1960, Ted Maiman
Laser parameters include what 3 things? - Correct answer-1)Duration of exposure
2)Fiber Diameter
3)Wavelength
Lasers are:
______chromatic?
_____directional?
coherent or noncoherent?
emitted from a stimulated ____________. - Correct answer-monochromatic: made of a
single wavelength (visible or infrared)
unidirectional
coherent (all peaks and valleys of each wave travel in unison)
active medium
What states can the active medium be in? - Correct answer-solid, gas, semiconductor
What type of active medium is used in Er: YAG? - Correct answer-solid state using
crystal matrix (erbium laced yttrium, aluminum and garnet)
, What type of gas is used when the active medium is sealed in an air tight chamber? -
Correct answer-CO2
Diode lasers have what type of active medium? - Correct answer-semiconductor
what photons form the laser? - Correct answer-light that leaks from the output coupler
Stimulated emission: - Correct answer-atoms of the active medium are stimulated to a
higher energy level--> released as a photon as the atom returns to a more stable lower
energy level.
Amplification - Correct answer-Released photons can go on to stimulate more atoms in
the crystal, thus producing more photons
Energy density depends on what 3 things? - Correct answer-energy, divergence
(tendency of a laser beam to spread outward=laser beam diameter increases), and
distance
Energy is measured in ______ - Correct answer-Joules (millijoules)
Power is ______ and is measured in _______ - Correct answer-rate of doing work, or
energy used over a period of time and is measured in Watts (J/sec)
Frequency is measured in _____. - Correct answer-Hertz ( laser pulses/sec)
What is the most important variable dictating how the laser beam will interact with the
target tissue? - Correct answer-Peak Power
Define Peak Power: - Correct answer-power level in each individual laser pulse,
however it is not visible to the operator
Describe Peak Power in the 3 types:
1) Continuous
2) Gated
3) Free running pulsed - Correct answer-1) the peak power equals the average power
displayed
2) Average power is half of peak power
3) Low Average power, very high peak power
What are the two basic forms of pulsed laser modes? - Correct answer-Gated wave
Free running pulsed
How is the gated wave pulse created? - Correct answer-created with a shutter that
blocks the laser beam from reaching the handpiece and target tissue at varying speeds:
the laser is on constantly but the shutter device blocks the light from transmitting.
(example: flashlight moving hand in front of it)
