Nonreciprocal light transmission based on the thermal radiative effect

Nonreciprocal light transmission is critical in building optical isolations and circulations in optical communication systems. Achieving high optical isolation and broad bandwidth with CMOS-compatibility are still difficult in silicon nano-photonics. Here we first experimentally demonstrate that the fiber-chip-fiber optomechanical structure, which is based on the thermal radiative effect, is effective at achieving a broad operation bandwidth of 24 nm and an ultra-high nonreciprocal transmission ratio up to 63 dB. These satisfactory nonreciprocal performances can mostly be attributed to the significant characteristics of the thermal radiative effect, which could cause a fiber displacement up to tens of microns. This powerful thermal radiative effect opens up a new opportunity for nonreciprocal light transmission which is promising to be used in complete on-chip nonreciprocal devices in the future.