Periodic Metallic Stepped Slits for Entire Transmission of Optical Wave and Efficient Transmission of Terahertz Wave

Abstract

The presence of metallic structures with array of slits, when slits have dimensions much less than the wavelength of the incident optical wave, typically causes extraordinary power transmission. This excellent power transmission indeed comes from the surface waves on the periodic structure excited by the transverse magnetic wave. Here we show that if slits are stepped, then the incident wave power is transmitted into the substrate at desired optical frequency entirely and simultaneously in terahertz frequency band by 70%, for ${\mathrm{I}\mathrm{n}}_{0.53}{\mathrm{G}\mathrm{a}}_{0.47}\mathrm{A}\mathrm{s}$ substrate. Power transmitted through the proposed structure is derived both in a closed form by an analytical model as well as numerically by finite element method. It is found that with the increase of field intensity in the substrate, the structure with array of stepped slits (as opposed to uniform slits) favorably has no reduction of frequency range at maximum transmitted power.

Keywords:

• Analytical model
• Optical wave
• Periodic array
• Stepped slits
• Terahertz wave
• Transmitted power

ACKNOWLEDEGMENTS

We thank the anonymous reviewers for many helpful comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Mohammadreza Khorshidi

Mohammadreza Khorshidi was born in Iran. He received the Master of Science (MSc) degree in 2009 from K N Toosi University of Technology and PhD degree in communication engineering in Shahed University, Iran. He is currently an assistant professor with the Department of Electrical Engineering, University of Birjand, Iran. His main research interest is terahertz technology with focus on photoconductive antennas and plasmonic structures.

Gholamreza Dadashzadeh

Gholamreza Dadashzadeh was born in Urmia, Iran. He received PhD degree in communication engineering from Tarbiat Modarres University, Tehran, Iran. He is currently an associate professor with the Department of Electrical Engineering, Shahed University, Tehran. He has published more than 70 papers in referred journals and international conferences in the area of antenna design and smart antennas. Email: [email protected]

Sajad Zafari

Sajad Zafari was born in Ardal, Iran. He received BS degree in communication engineering from Quchan University of Technology, Khorasan Razavi, Iran. He is studying Master of Science in communication engineering in Shahed University, Tehran, Iran. His current research interest is on terahertz technology, with focus on photoconductive antennas and plasmonic structure. Email: [email protected]