Nichia Corp. of Anan, Japan, has dragged former employee Shuji Nakamura into the bitter litigation over blue laser diode manufacturing technology, accusing him of revealing trade secrets to rival Cree Inc. Meanwhile, Cree has allied itself with a rival Japanese manufacturer to share photonics patents and to develop blue laser diodes. Nichia and Cree have been embroiled in litigation since Nichia sued a Cree distributor in Japan in 1999 over LED patents. Nichia's December 2000 legal action was a response to a September lawsuit in which Cree and North Carolina State University accused Nichia of violating a US patent for manufacturing GaN semiconductor structures. Those structures are the basis of Nichia's commercial blue diode lasers. Nakamura developed and commercialized the blue laser technology while working at Nichia. He has since left the company to become a professor at the University of California at Santa Barbara. In October, Cree announced that it had also mustered Nakamura's services, at least part time. Around the same time, it announced a significant lifetime breakthrough in its own blue diode laser research program. Nichia's counterclaims to the Cree lawsuit allege that Nakamura revealed trade secrets to Cree. Furthermore, it accuses Cree of infringing four US patents: A 1994 Nichia patent (No. 5,306,662) for a method of manufacturing P-type compound semiconductors. 1996 and 1998 Nichia patents (Nos. 5,578,839 and 5,747,832) for light-emitting GaN-based compound semiconductor devices. A 1998 Nichia patent (No. 5,767,581) for a GaN-based III-V group compound semiconductor. The counterclaims landed in US District Court in North Carolina just days after Cree announced an alliance with electronics manufacturer Rohm Co. Ltd. of Kyoto, Japan, that grants Cree licenses to US and Japanese photonics patents. The companies agreed to cooperatively develop packaged blue laser diodes for consumer applications.