LASERS CERTIFICATION EXAM Q&A 2023 UPDATE

LASERS CERTIFICATION EXAM Q&A 2023 UPDATE Theorized the concept of stimulated emission - ANS-Einstein Theorized that an excited electron will spontaneously return to its ground state - ANSBohr First ruby laser was created in _____ by ______. - ANS-1960, Ted Maiman _________ reported in 1965 that a ruby laser could vaporize enamel. - ANS-Stern and Sognnaes First pulsed Nd:YAG laser released in ______ and cuts ______ tissue. - ANS-1990, soft tissue In _____ the first dental hard tissue was FDA cleared and is called _______. And the ______ laser a year later. - ANS-1997 Er: YAG laser Er, Cr: YSGG The word LASER is an acronym standing for _________. - ANS-Light Amplification by Stimulated Emission of Radiation Laser parameters include what 3 things? - ANS-1)Duration of exposure 2)Fiber Diameter 3)Wavelength Lasers are: ______chromatic? _____directional? coherent or noncoherent? emitted from a stimulated ____________. - ANS-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? - ANS-solid, gas, semiconductor What type of active medium is used in Er: YAG? - ANS-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? - ANS-CO2 Diode lasers have what type of active medium? - ANS-semiconductor what photons form the laser? - ANS-light that leaks from the output coupler Stimulated emission: - ANS-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 - ANS-Released photons can go on to stimulate more atoms in the crystal, thus producing more photons Energy density depends on what 3 things? - ANS-energy, divergence (tendency of a laser beam to spread outward=laser beam diameter increases), and distance Energy is measured in ______ - ANS-Joules (millijoules) Power is ______ and is measured in _______ - ANS-rate of doing work, or energy used over a period of time and is measured in Watts (J/sec) Frequency is measured in _____. - ANS-Hertz ( laser pulses/sec) What is the most important variable dictating how the laser beam will interact with the target tissue? - ANS-Peak Power Define Peak Power: - ANS-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 - ANS-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? - ANS-Gated wave Free running pulsed How is the gated wave pulse created? - ANS-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) How is the Free running pulse created? - ANS-Not on constantly, but emit photons in powerful bursts of energy measured in millionths of seconds. (example: turning flashlight on and off)...