A coaxial-type 1.3/1.55 μm WDM-PD module for optical access networks

A new 1.3/1.55 /spl mu/m WDM/photodiode(PD) module has been designed and fabricated for use in optical access networks. A 1.3 /spl mu/m-PD and a 1.55 /spl mu/m-PD were arranged in series along the optical axis in a coaxial package. The 1.3 /spl mu/m-PD with an In/sub 0.66/Ga/sub 0.34/As/sub 0.76/P/sub 0.24/ photosensitive layer (/spl lambda//sub g/=1.42 /spl mu/m) absorbs 1.3 /spl mu/m digital optical signals and it is transparent to 1.55 /spl mu/m wavelength. The 1.55 /spl mu/m-PD with an In/sub 0.53/Ga/sub 0.47/As photosensitive layer absorbs 1.55 /spl mu/m analog optical signals. Responsivity of the module is 0.82 A/W at 1.31 /spl mu/m wavelength and 0.75 A/W at 1.55 /spl mu/m wavelength, respectively. IMD2 of the 1.55 /spl mu/m-PD measured by two-tone method was -76.1 dBc at Pf(1.55 /spl mu/m) of -6 dBm. Bit error rate (BER) of the 1.3 /spl mu/m-PD was measured at 28.8 Mb/s by using an amplifier with bandwidth of 200 MHz and was found to be less than 10/sup -8/ at Pf(1.3 /spl mu/m) of -30 dBm.