With consideration of the modulation frequency of the input lightwave itself, we present a new model to calculate the quantum efficiency of RCE p-i-n photodetectors (PD) by superimposition of multiple reflected lightwaves. For the first time, the optical delay, another important factor limiting the electrical bandwidth of RCE p-i-n PD excluding the transit time of the carriers and RCd response of the photodetector, is analyzed and discussed in detail. The optical delay dominates the bandwidth of RCE p-i-n PD when its active layer is thinner than several 10 nm. These three limiting factors must be considered exactly for design of ultra-high-speed RCE p-i-n PD.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers.We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide.The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm.Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm.Therefore,our invariable coupling power technique is simpler than Intel's.
RAN Qi-jiang HAN Pei-de QUAN Yu-jun GAO Li-peng ZENG Fan-ping ZHAO Chun-hua