RESUMEN
All-optical wavelength conversion for 2×11.64 GBaud adaptively-modulated orthogonal frequency division multiplexing (AM-OFDM) signals with QPSK/16QAM formats is experimentally demonstrated in a silicon waveguide. The AM-OFDM signal with partly higher- (and lower-) order formats on lower- (and higher-) frequency subcarriers has better overall conversion performance in receiving optical signal-to-noise ratio and power penalty. In comparison with the OFDM-QPSK signal, at the BER of 3.8×10-3, the bit rate increases 11.64 Gbit/s per channel almost without conversion power penalty increased by replacing the QPSK sequence with the 16QAM sequence on half subcarriers.
RESUMEN
A silicon-based on-chip reconfigurable optical add-drop multiplexer (ROADM) is presented for hybrid wavelength-division-multiplexing-mode-division-multiplexing systems. The present ROADM consists of a four-channel mode demultiplexer, four wavelength-selective thermo-optic switches based on microring resonators, and a four-channel mode multiplexer. With the present ROADM, one can add/drop one of wavelength channels of any mode to/from the multimode bus waveguide successfully with an excess loss of 2-5 dB and an extinction ratio of â¼20 dB over a wavelength range of 1525-1555 nm.
RESUMEN
Wavelength conversion and five-channel multicasting for 20 Gbit/s quadrature phase-shift keying signals have been experimentally demonstrated based on four-wave mixing in a silicon waveguide with digital coherent detection. The eye diagrams and constellation diagrams of the converted and multicasting idlers are successfully observed. Moreover, the bit-error rates (BERs) of the generated idlers are measured and the power penalties are all less than 0.7 dB at a BER of 3×10(-3).