Multi-Band Photonic Integrated Wavelength Selective Switch

As fiber-optic systems turn toward multi-band transmission (MBT), exploiting the complete low loss window of optical fibers, novel optical components, able to operate in bands other than the conventional C-band, become necessary. In light of this, we report on a multi-band photonic integrated
$\mathbf {1\times 2}$
wavelength selective switch (WSS) operating in the O, S, C and L-bands. The photonic integrated WSS presented in this work uses a folded arrayed-waveguide grating (AWG) as the filtering element, while the wideband operation of the thermo-optic switches allows the routing of the individual channels from those bands to any of the device output ports. The operation of the WSS is experimentally validated for different bands and modulation formats. Results show error-free operation with limited penalty with intensity-modulation direct-detection (IM/DD) non-return-to-zero on-off keying (NRZ-OOK) up to 35 Gb/s in O, S, C and L-bands and up to 169.83 Gb/s with coherent 64-quadrature amplitude modulation (QAM) data transmission in the S, C and L-bands.