High speed GaAs PIN photodiodes

Using 4 level pulse amplitude modulation (PAM4), which enables the transmission of 2 bits per clock cycle, these new GaAs photodiodes enable data transfer rates of up to 25Gbps! These photodiodes feature extremely low capacitance and dark current and are designed to achieve a high responsivity of 0.6A/W at the 850nm wavelength of their complementary high speed vertical cavity surface emitting lasers (VCSELs).  These photodiodes only require a relatively low -2V reverse bias and they are available as single chips or in electrically isolated linear arrays of up to 12 chips on a ceramic submount.