On-off switching of orbital-angular-momentum light via atomic collision

Data transmission using optical switching devices is currently the ultimate goal of most telecommunication research. Here we show that the collision effect of hot atoms, which is undesirable for most studies, can induce on -off switching of optical orbital angular momentum (OAM) light. By adjusting the temperature of atomic cell and the detuning of signal field, the transmission of signal field carrying OAM can be efficiently switched. In particular, we can achieve the "zero"transmission bandwidth of over 1 GHz. Due to the unique optical properties of OAM light, our proposal will open up a new avenue toward optical OAM switching devices and provides opportunities for applications in integrated optics and high-dimensional information networks based on OAM light.