Practice Test Geeks(CLT) Certified Laser Technician Practice Test
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Laser Physics & Types 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 & Types flashcards as text

  1. What is the primary gain medium in an erbium-doped fiber amplifier (EDFA), and at what wavelength does it operate?

    Answer: Er³⁺ ions at ~1550 nm

    EDFAs use erbium ions (Er³⁺) doped into silica fiber and amplify signals near 1550 nm, which coincides with the low-loss window of optical fiber.

  2. In a Q-switched laser, what happens when the Q-switch opens?

    Answer: Cavity loss suddenly drops, releasing stored energy as a short intense pulse

    Opening the Q-switch removes the artificially high intracavity loss, causing the large stored population inversion to deplete rapidly as a high-peak-power pulse.

  3. Which laser type uses an organic dye dissolved in a solvent as the gain medium?

    Answer: Dye laser

    Dye lasers use fluorescent organic dyes in liquid solution as the gain medium and are tunable over a broad wavelength range.

  4. What does the term 'TEM₀₀ mode' indicate about a laser beam?

    Answer: The beam has a Gaussian intensity profile with the smallest beam waist

    TEM₀₀ is the fundamental transverse electromagnetic mode, characterized by a Gaussian profile and the lowest beam divergence for a given aperture.

  5. Excimer lasers produce UV radiation by using which type of gain medium?

    Answer: Unstable noble-gas halide molecules

    Excimer lasers use excited dimers or exciplexes—bound excited states of noble-gas halides like ArF or KrF—that dissociate after emitting a UV photon.

  6. What is the significance of the 'threshold pump power' in a laser?

    Answer: The minimum pump power at which gain exactly equals loss and lasing begins

    Threshold pump power is the minimum excitation level at which the round-trip gain equals round-trip loss, allowing sustained laser oscillation.

  7. A titanium-sapphire (Ti:Sapphire) laser is valued primarily for which characteristic?

    Answer: Its broad tunability from approximately 650 to 1100 nm

    Ti:Sapphire has an exceptionally broad gain bandwidth spanning roughly 650–1100 nm, making it widely tunable and capable of producing ultrashort pulses.