Laser history (first working laser): What was the active medium used in the first operational laser? Identify the gain medium in Theodore Maiman's 1960 demonstration. Choose the correct medium.
Interview
Technology
Difficulty: Easy
Choose an option
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AHelium–Neon gas
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BCO₂ gas
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CNd:YAG crystal
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DRuby (Cr³⁺:Al₂O₃) crystal
Answer
Correct Answer: Ruby (Cr³⁺:Al₂O₃) crystal
Explanation
Given data
- Pioneer: Theodore H. Maiman, 1960.
Concept/ApproachThe first functioning laser was a solid-state ruby laser, using chromium-doped sapphire (Cr³⁺:Al₂O₃) as the active/gain medium.
Reasoning• Gas lasers (He–Ne, CO₂) and Nd:YAG came later; Maiman's breakthrough used synthetic ruby.
Final AnswerRuby (Cr³⁺:Al₂O₃) crystal