We report the demonstration of the uplink of a low-cost passive optical network (PON), utilizing a superluminescent light emitting diode (SLED) as a broadband light source, a coarse wavelength division multiplexer (CWDM) to slice the spectrum into standard CWDM channels, and a reflective semiconductor optical amplifier (RSOA) as modulator and amplifier at the remote site. We demonstrate 2.5-Gbps transmission over 1 km of single-mode fiber for all four channels of the CWDM link (1511, 1531, 1551, and 1571 nm), with the bit rate error (BER) of the system measured to be below 10−12. The main applications for this communication system are remote monitoring systems.
We present a method to fabricate in situ lens arrays on the edge of waveguide arrays that are embedded in a printed circuit board. This fabrication method can guarantee precise alignment between the lenslet and the waveguide arrays, by directly overlaying the lenslet pattern on the waveguide cores. Each fabricated lenslet has a numerical aperture of 0.1, and the beam through it has a divergence angle of 3.29 deg, close to that of a perfectly aligned commercial lenslet array.