Abstract: In a light communication system,two important parameters of the photoelectricity detector are quanta efficiency and respond rate.The thickness of the absorb layer must be augmented to obtain higher quanta efficiency,which prolongs the transit time of the carriers,thus slowing the respond rate.RCEPD can solve the problem of the restriction between the quanta efficiency and the response rate.In this paper,the author design a long wavelength RCEPD,and with sufficiently considering the difficulties in the making craftwork,and analyzing the factors of RCEPD in each aspect,we optimize the whole design.

Key words: resonant cavity enhanced photo detector(RCE PD), quanta efficiency, stationary wave effect