"Master wafer, method of manufacturing the same, and method of manufacturing optical device by using the same"
Joonyong Park, Dongouk Kim, Jihyun Bae, Bongsu Shin, Jong G. Ok, Ilsun Yoon, Sunghoon Lee, Jaeseung Chung, Sukgyu Hahm
, US patent
, granted; US 10007124 B2