One-dimensional cuprate as a nonlinear optical material for ultrafast all-optical switching

We examine the feasibility of ultrafast all-optical switching utilizing a one-dimensional cuprate Sr₂CuO₃ operable within the optical fiber communication window at room temperature by using the pump-probe spectroscopy and Z-scan measurements. The strength of the interband two-photon absorption in Sr₂CuO₃ is much larger than that of conventional semiconductors, and is comparable to the largest reported values in π-conjugated polymers. The intensity-dependent refractive index, however, is considerably larger than that of polymeric materials. We further show that the recovery of optical transparency after the photoinjection of carriers lies within picosecond time scale. Large nonlinearity, ultrafast response, and high damage threshold make the one-dimensional cuprate a potential material for multiterabits/second rate all-optical switch.