FIELD-EFFECT TRANSISTOR SELF ELECTROOPTIC EFFECT DEVICE (FET-SEED) DIFFERENTIAL TRANSIMPEDANCE AMPLIFIERS FOR 2-DIMENSIONAL OPTICAL-DATA LINKS

A 4 x 18 two-dimensional array of GaAs FET-SEED (Field Effect Transist or-Self Electrooptic Effect Device) differential transimpedence receiv ers has been fabricated for application in massively parallel optical data link board-to-board interconnections. Several FET-SEED receiver a rrays were tested and displayed a mean response of similar to 0.7 mV/m u W, and were capable of >100 Mbps per channel operation, The mean rec eiver sensitivity for a BER of < 10(-9) was calculated from the measur ed noise spectrum to be -26.8 dBm at the system design rate of 40 Mbps (18 k-22 MHz bandwidth), and -23.2 dBm for a 100 Mbps rate (dc-66 MHz bandwidth). A sensitivity of approximately -25 dBm for the 40 Mbps ra te was confirmed using a bit-error-rate test set. The theoretical nois e is compared to measured values with good agreement assuming a FET ch annel noise factor of 1.4. The 1/f noise corner frequency of similar t o 13 MHz was found to cause a similar to 1.2 dB degradation in sensiti vity for the 100 Mbps rate, The differential amplifier mean de output offset voltage was measured to be 10 mV, and displayed a large sigma d ue to parameter variations in the active devices, Two receiver arrays were successfully used in a demonstration of a fully differential para llel optical Small Computer System Interface (SCSI) data link.