Abstract
An optical diode structure with two dislocated parallel metallic gratings is proposed and investigated numerically. Dichroic optical diode transmission is realized in this structure, i.e., optical diode effect is observed in two wavebands corresponding to inverse transmission directions. In the structure, two parallel metallic gratings with different grating constants are separated by a dielectric slab in between. The first illuminated grating acts as a selector for exciting surface plasmons at a proper wavelength. The other grating acts as an emitter to realize optical transmission. When the incident direction is reversed, the roles of two gratings exchange and surface plasmons are excited at another wavelength. In dichroic transmission wavebands, the optical diode structure exhibits extraordinary transmission and possesses high optical isolation up to 1. Furthermore, the operating wavebands can be modulated by changing structure parameters.
Highlights
Optical diode, which transmits photons toward one direction and forbids the transmission in the reverse direction, has attracted considerable attention by virtue of the unidirectional transmission property [1]
Plasmonic devices are proposed in many research fields such as metasurface holography [10,11,12,13,14], refractive index sensor [15, 16], and filter [17, 18]
The dichroic optical diode transmission based on surface plasmons (SPs) is realized in our structure, which consists of two dislocated parallel silver gratings and a silica interlayer
Summary
Optical diode, which transmits photons toward one direction and forbids the transmission in the reverse direction, has attracted considerable attention by virtue of the unidirectional transmission property [1]. Optical diode phenomena can be observed when time-reversal symmetry of light-matter interaction is broken. External magnetic field [2], bias voltage [3], acoustic wave [4], or time-dependent modulation [5, 6] can be applied to achieve the optical diode effect. Metallic micro-nano structures gained great interest due to the promising properties of surface plasmons (SPs). Plasmonic devices can strongly modify the interaction of electromagnetic fields in nanoscale [19].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
