Progress In Electromagnetics Research Symposium 2007, Beijing, China, March 26-30 1133 Manufacturing and Characterisation of Electromagnetic Metamaterials from the Far to the Near Infrared H. O. Moser, B. D. F. Casse, M. Bahou, Ao Chen, P. D. Gu, L. K. Jian Shahrain bin Mahmood, and Li Wen Singapore Synchrotron Light Source, National University of Singapore 5 Research Link, Singapore 117603, Singapore Abstract— SSLS is micro/nanomanufacturing electromagnetic metamaterials (EM 3 ) since 2002. Micro/nanofabrication enables building EM 3 structures that cover the spectral range from the far infrared at about 1 THz to the visible at 430 THz and beyond. Although the visible is par- ticularly attractive as the optical effects of EM 3 may be directly observed by the eye, applications such as the sub-diffraction limit imaging are of interest over the whole THz range. One of the key issues for the future success of EM 3 is the availability of good quality materials in sufficient quantities. To reach this goal, SSLS is using its micro/nano-fabrication equipment that includes the full LIGA process in which X-ray deep lithography plays an important role for the parallel production of EM 3 on wafers and hot embossing may enable mass fabrication. Primary pattern generation at SSLS includes laser direct writing and electron beam lithography. SSLS has adopted Pendry’s split-ring-resonator approach [1] and developed a planar geometry that is easily suitable for lithography and combines rods and split-ring resonators [2]. The frequency range covered by SSLS-made EM 3 spans from 2 to 216 THz. Although fabrication of nested split rings becomes tighter as the frequency goes up the capability of e beam writing should be sufficient to reach the visible. The basic set up is a planar sheet of structures either embedded in a matrix or deposited on a substrate. This requires oblique incidence of the electromagnetic wave in order to achieve good coupling. An alternative approach is being pursued that uses inclined X-ray lithography such as to produce structures that have their axes inclined with respect to the matrix plane to provide good coupling for a wave coming in at normal incidence [3, 4]. This may also help reducing anisotropy of the response of the material. Chips of matrix-held EM 3 s were up to 4 × 4 mm 2 large and typically 25 μm thick. They were characterised by means of infrared Fourier transform interferometry at the ISMI beamline of SSLS. Stacking of up to three chips showed that the resonant transmission peak gets relatively stronger whereas the overall transmission is decreasing due to matrix absorption, as expected. Thus, matrix materials will be required that are as thin and transparent as possible. This may ultimately require the use of hot embossing since spectrally suitable matrix materials may not be good X-ray resists. REFERENCES 1. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, IEEE Trans. Microwave Theory Tech., Vol. 47, 2075, 1999. 2. Moser, H. O., B. D. F. Casse, O. Wilhelmi, and B. T. Saw, Phys. Rev. Lett., Vol. 94, 063901, 2005. 3. Moser, H. O., B. D. F. Casse, O. Wilhelmi, and B. T. Saw, ICMAT 2005, Proceedings of the Symposium R Electromagnetic Materials, 18–25, World Scientific, Singapore 2005, ISBN 981-256-411-X(pbk). 4. Casse, B. D. F., H. O. Moser, O. Wilhelmi, and B. T. Saw, ICMAT 2005, Proceedings of the Symposium R Electromagnetic Materials, 55–58, World Scientific, Singapore 2005, ISBN 981-256-411-X(pbk).