The Chinese market for optical communications chip is mainly dependent on foreign suppliers. There is almost no manufacturers produce PON core chips. Four major EPON chip vendors, including Cortina, PMC-Sierra, Teknovus (Broadcom acquisition) as well as Chinese manufacturers Opulan, but Opulan was acquisitd by Atheros. GPON Chip providers is relatively dispersed, including Broadlight, PMC-Sierra, Broadcom, Marvel,Cortina, Infineon, Ikanos' almost ten manufacturers. In the field of optical communications transceiver chip, Phyworks, Mindspeed, Vitesse are the major suppliers. Phyworks, the world's largest supplier of passive optical network user optical module chip, shipped about 2 million chips each month in China.The PLC chip based on planar lightwave guide is also primarily from imports, including of NTT Electronics, Hitachi, Cable, Neo Photonics, JDS Uniphase, Teem, Wooriro. As to the light active device chips,2.5Gb / s or below LD chip, APD chip rely on imports.