Researchers at NTT Photonics Laboratories in Tokai, Japan, have demonstrated a 1010-channel filter for optical telecommunications that they believe will enable ultrahigh-density networking. They reported the device in the June issue of IEEE Photonics Technology Letters.

They connected 10 1 x 160 arrayed-waveguide gratings with 10-GHz channel spacing to a 1 x 10 arrayed-waveguide grating with 1-THz channel spacing. The filter covers the C- and L-bands and displays a loss of 13 to 19 dB per channel, which the researchers hope to reduce by 9 dB. Adjacent and accumulated crosstalk varied from -32 to -25 dB and -24 to -18 dB, respectively.