Laser Physics & Safety Flashcards
7 cards from real CLT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Laser Physics & Safety flashcards as text
Which concept defines the maximum laser exposure that will not cause biological damage to the eye or skin under specified conditions?
Answer: Maximum Permissible Exposure (MPE)
The MPE is the highest power or energy density to which a person may be exposed without hazardous biological effects, as defined in ANSI Z136.1.
What is 'optical density' (OD) as it relates to laser eyewear?
Answer: Logarithmic measure of the lens's ability to attenuate laser radiation
Optical density (OD) = log₁₀(incident irradiance / transmitted irradiance); an OD of 4 means 10,000-fold attenuation of the laser beam.
Which phenomenon allows a laser to emit a single longitudinal mode, producing an extremely narrow linewidth?
Answer: Use of an etalon or narrow bandpass filter inside the cavity
An intracavity etalon (Fabry-Pérot étalon) selects a single longitudinal mode by introducing high losses at all other cavity resonances.
During a laser plume hazard assessment, the primary concern when ablating biological tissue is:
Answer: Inhalation of mutagenic and infectious particulates in the plume
Laser plumes from biological tissue contain viable cellular fragments, toxic chemicals, and carcinogenic particles that pose an inhalation hazard.
Which property of a laser beam is described by M² (M-squared)?
Answer: Beam quality relative to an ideal Gaussian beam
M² quantifies how closely a beam resembles a perfect TEM₀₀ Gaussian beam; an ideal beam has M²=1, and real beams have M²>1.
Which administrative control is required in a laser controlled area according to ANSI Z136.1?
Answer: Posting of laser hazard warning signs at all entry points
ANSI Z136.1 requires that laser controlled areas display appropriate warning signs to alert personnel to the hazard before entry.
Which wavelength range is absorbed primarily by the cornea and aqueous humor, making it most hazardous to those structures rather than the retina?
Answer: Far-infrared (>1400 nm) and UV-C (<280 nm)
Far-IR and UV-C wavelengths are strongly absorbed by the cornea and aqueous humor before reaching the retina, causing photokeratitis and corneal damage.