Opto-VLSI-based N × M wavelength selective switch

Programmable High-Resolution Spectral Processor in C-band Enabled by Low-Cost Compact Light Paths

The flexible photonics spectral processor (PSP) is an indispensable element for elastic optical transmission networks that adopt wavelength division multiplexing (WDM) technology. The resolution and system cost are two vital metrics when developing a PSP. In this paper, a high-resolution 1 × 6 programmable PSP is investigated and experimentally demonstrated by using low-cost compact spatial light paths, which is enabled by a 2 K (1080p) liquid crystal on silicon (LCoS) and two cascaded transmission gratings with a 1000 line/mm resolution. For each wavelength channel, the filtering bandwidth and power attenuation can be manipulated independently. The total insertion loss (IL) for six ports is in the range of 5.9~9.4 dB over the full C-band. The achieved 3-dB bandwidths are able to adjust from 6.2 GHz to 5 THz. Furthermore, multiple system experiments utilizing the proposed PSP, such as flexible spectral shaping and optical frequency comb generation, are carried out to validate the feasibility for the WDM systems.

Demonstration of a 3 × 4 tunable bandwidth WSS with tunable attenuation using compact spatial light paths

M × N wavelength selective switch (WSS) is a core component to address wavelength conflict in an optical switching node. In this paper, we design and experimentally demonstrate a performance enhanced 3 × 4 tunable bandwidth WSS (TBWSS) with tunable attenuation across the full C-band, and using compact spatial light paths. Wavelength channels from any input optical fiber port can be switched into any output optical fiber port with best insertion loss (IL) of 8.4 dB and worst IL of 12.5 dB. The attenuation tuning range can reach up to 35 dB. Compared to previous demonstrations, more than 2 dB IL improvement is achieved. Based on the proposed compact spatial light paths, the number of input and output ports can be easily extended to 10 and 20, respectively.