RESUMO
We present a novel multi-level diffractive optical element for diffractive optic near-field lithography based fabrication of large-area diamond-like photonic crystal structure in a single laser exposure step. A multi-level single-surface phase element was laser fabricated on a thin polymer film by two-photon polymerization. A quarter-period phase shift was designed into the phase elements to generate a 3D periodic intensity distribution of double basis diamond-like structure. Finite difference time domain calculation of near-field diffraction patterns and associated isointensity surfaces are corroborated by definitive demonstration of a diamond-like woodpile structure formed inside thick photoresist. A large number of layers provided a strong stopband in the telecom band that matched predictions of numerical band calculation. SEM and spectral observations indicate good structural uniformity over large exposure area that promises 3D photonic crystal devices with high optical quality for a wide range of motif shapes and symmetries. Optical sensing is demonstrated by spectral shifts of the Gamma-Zeta stopband under liquid emersion.
RESUMO
Fabry-Perot etalons have been fabricated with 3D colloidal photonic crystal mirrors. The colloid films were optimized for high reflection and low loss to provide good finesse values in the 1200-1700 nm spectral range. A cavity quality factor of 2400 and a finesse of 8 together with sharp 0.5 nm wide resonance transmission peaks are reported that attest to the relatively good optical quality of the three-dimensionally structured films and the promise of self-assembly colloidal crystal chemistry in providing novel microporous optical interferometers for potential applications such as environmental and biological sensing.
