question: In what decade were breakthroughs made that brought in the modern era of GaN-based optoelectronic devices ?
answer: 1980s
turker_answer: Breakthroughs were made in the 1980 's that brought in the modern era of GaN-based optoelectronic devices .
rule-based: Were breakthroughs made that brought in the modern era of GaN-based optoelectronic devices in 1980s .