Question: what type of laser is used in cd and dvd players
[{'answer': 'semiconductor', 'provenance': [{'wikipedia_id': '299592', 'title': 'Optical disc drive', 'start_paragraph_id': 14, 'start_character': 130, 'end_paragraph_id': 14, 'end_character': 143, 'bleu_score': 1.0, 'section': 'Section::::Key components.:Laser and optics.\n'}]}, {'provenance': [{'wikipedia_id': '299592', 'title': 'Optical disc drive', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 260, 'bleu_score': 0.955027111100031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15538939000284404306}, 'section': 'Section::::Key components.:Laser and optics.\n'}]}]