Sample interview questions: What are some common techniques for achieving ultrashort laser pulses?
Sample answer:
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Kerr-lens mode-locking: This technique utilizes the intensity-dependent refractive index of a material to create a self-focusing effect, resulting in the formation of a soliton-like pulse. By carefully controlling the cavity parameters, it is possible to generate ultrashort pulses with durations down to a few femtoseconds.
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Passive mode-locking: In this approach, an element with a saturable absorber is incorporated into the laser cavity. The saturable absorber selectively transmits light above a certain intensity threshold, leading to the formation of stable mode-locked pulses. This technique is commonly employed in solid-state and fiber lasers, offering simplicity and cost-effectiveness.
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Active mode-locking: Active mode-locking utilizes an external modulator to modulate the gain or loss in the laser cavity at a specific frequency. This allows for precise control over the … Read full answer