Optical tuning of ultra-thin, silicon-based flexible metamaterial membranes in the terahertz regime

We present a fabrication method for flexible optically tunable terahertz metamaterial membranes based on thinning and embedding of commercially available silicon wafers in the metamaterial structure. The resulting membrane thickness of less than 25 em allows for quasi etalon-effect free devices which can be designed to show impedance matching to the surrounding air. We fabricated a thin film spectral bandpass filter with a maximal transmission of 85% and a modulation depth upon optical tuning of 98% at an operating frequency of 0.65THz. Further, we discussed the charge carrier dynamics and the requirements for optical tuning.

[1]  Sandra Wolff,et al.  Polarization-independent active metamaterial for high-frequency terahertz modulation. , 2009, Optics express.

[2]  van Exter M,et al.  Carrier dynamics of electrons and holes in moderately doped silicon. , 1990, Physical review. B, Condensed matter.

[3]  Ekmel Ozbay,et al.  Optically implemented broadband blueshift switch in the terahertz regime. , 2011, Physical review letters.

[4]  M. Schubert,et al.  Minority carrier lifetime in silicon wafers from quasi-steady-state photoluminescence , 2010 .

[5]  Abul K. Azad,et al.  Experimental demonstration of frequency-agile terahertz metamaterials , 2008 .

[6]  Yuri S. Kivshar,et al.  Active and tunable metamaterials , 2011 .

[7]  D. Grischkowsky,et al.  Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors , 1990 .

[8]  Remigius Zengerle,et al.  Negative index bulk metamaterial at terahertz frequencies. , 2008, Optics express.

[9]  Nikolay I Zheludev,et al.  The Road Ahead for Metamaterials , 2010, Science.

[10]  Irena Zubel,et al.  The effect of isopropyl alcohol on etching rate and roughness of (1 0 0) Si surface etched in KOH and TMAH solutions , 2001 .

[11]  Xin Zhang,et al.  Frequency tunable terahertz metamaterials using broadside coupled split-ring resonators , 2011 .

[12]  D. Schroder,et al.  Silicon‐on‐sapphire with microsecond carrier lifetimes , 1973 .

[13]  Michael Wraback,et al.  Optically Tunable Terahertz Metamaterials on Highly Flexible Substrates , 2013, IEEE Transactions on Terahertz Science and Technology.

[14]  Dieter K. Schroder,et al.  Carrier lifetimes in silicon , 1997 .

[15]  M. Yun.  Investigation of KOH Anisotropic Etching for the Fabrication of Sharp Tips in Silicon-on-Insulator (SOI) Material , 2000 .

[16]  M. Rahm,et al.  Metamaterial-based gradient index lens with strong focusing in the THz frequency range. , 2010, Optics express.

[17]  J. Pendry,et al.  Low frequency plasmons in thin-wire structures , 1998 .

[18]  Fuad E. Doany,et al.  Carrier Lifetime vs. Ion-Implantation Dose in Silicon on Sapphire , 1987, Topical Meeting on Picosecond Electronics and Optoelectronics.

[19]  Ari Sihvola,et al.  Metamaterials in electromagnetics , 2007 .

[20]  Xiang Zhang,et al.  Photoinduced handedness switching in terahertz chiral metamolecules , 2012, Nature Communications.

[21]  Stewart,et al.  Extremely low frequency plasmons in metallic mesostructures. , 1996, Physical review letters.

[22]  Qingli Zhou,et al.  Ultrafast optical modulation of terahertz metamaterials , 2011 .

[23]  Chang,et al.  Unusually low surface-recombination velocity on silicon and germanium surfaces. , 1986, Physical review letters.

[24]  Abul K. Azad,et al.  Dynamically reconfigurable terahertz metamaterial through photo- doped semiconductor , 2011 .

[25]  Marco Rahm,et al.  Metamaterial-based gradient index beam steerers for terahertz radiation , 2013 .