Jacson W. Menezes

Comparison of Plasmonic Arrays of Holes Recorded by Interference Lithography and Focused Ion Beam

In this paper, we compare the geometric characteristics and the optical properties of plasmonic hole arrays recorded in gold (Au) films using two different techniques, namely, focused ion beam (FIB) and interference lithography (IL). The morphology of the samples was analyzed using a scanning electron microscope (SEM), and the plasmonic peaks were measured from the transmission spectrum of the samples. The diameters of the holes recorded by IL present approximately the same statistical deviation as those fabricated by FIB but in a much larger area. Although the transmittance measurements of both types of samples exhibit the characteristic plasmonic peaks, the intrinsic fabrication errors of each technique affect differently the optical spectra.

Template-Stripping Fabricated Plasmonic Nanogratings for Chemical Sensing

Template stripping has been applied to transfer one-dimensional nanograting structures fabricated by interference lithography (IL) onto planar supports (i.e., glass slides and plane-cut optical fiber tips). A thin adhesive layer of epoxy resin was used to facilitate the transfer. The UV-Vis spectroscopic response of the nanogratings supported on glass slides demonstrated a strong dependency on the polarization of the incident light. The bulk refractive index sensitivities of the nanogratings supported on glass were dependent on the type of metal (Ag or Au) and the thickness of the metal film. The described methodology provides an efficient low-cost fabrication alternative to produce metallic nanostructures for plasmonic chemical sensing applications.

Er 3+ -doped micro-structured tellurite fiber: laser generation and optical gain

Optical results concerning the generation of laser and optical gain by using an Er3+-doped tellurite micro-structured fiber are reported for the first time. For this purpose a scheme that consist of two 980 nm diode pump lasers (simultaneously in the co-propagating and the counter-propagating directions) and short Er3+-doped tellurite micro-structured fibers (fabricated by using the stack-and-draw technique and a soft glass drawing tower) was used. The laser produced here was obtained within the range 1530 to 1565 nm, and the maximum optical gain obtained was higher than 8 dB.

Optical Amplifier based on a Er3+- doped Tellurite Microstructured Optical Fiber

Optical gain from 1530 up to 1570 nm by using an Er3+-doped tellurite microstructured fiber is presented. A maximum optical gain of ~27 dB at 1554 nm is obtained for a 980/1480 nm pump scheme.

Photonic crystals and plasmonic structures recorded by multi-exposure of holographic patterns

Different technologies can be used for fabrication of photonic crystals such as: self-assembly of colloidal particles, ebeam lithography (EB), interference lithography (IL) and focused ion beam (FIB). Among them, the holographic lithography (HL) is the only technique that is able to fabricate both two-dimensional and three-dimensional photonic crystals, as well as plasmonic structures, in large areas. In this paper we demonstrate the use of the multi-exposure of two-beam interference patterns, with rotation of the sample around different axis, for fabrication of large areas 2D and 3 D photonic crystals and plasmonic structures. Using this technique, we achieved aspect ratios of about 4 in 2D photoresist templates recorded in 1 cm2 glass substrates. In order to generate the 2D photonic band gap layers and plasmonic structures, we combine the use the high aspect ratio photoresist templates with shadow evaporation of appropriated materials, with a further lift-off of the photoresist. The optical properties of the recorded structures, both photonic and plasmonic, were measured to demonstrate the applicability of the technique.

Plasmonic structures fabricated by interference lithography for sensor applications

In this work we demonstrate the use of holographic lithography for generation of large area plasmonic periodic structures. Submicrometric array of holes, with different periods and thickness, were recorded in gold films, in areas of about 1 cm2, with homogeneity similar to that of samples recorded by Focused Ion Beam. In order to check the plasmonic properties, we measured the transmission spectra of the samples. The spectra exhibit the typical surface plasmon resonances (SPR) in the infrared whose position and width present the expected behavior with the period of the array and film thickness. The shift of the peak position with the permittivity of the surrounding medium demonstrates the feasebility of the sample as large area sensors.

Laser generation with a microstructured Er 3+ -doped tellurite optical fiber

We fabricate a microstructured Erbium-doped tellurite fiber and demonstrate laser emission. A simple double-pump configuration (980 nm) is used. A 5 cm fiber generates a laser at 1553.3 nm with an OSNR of ~21 dB.

2D Photonic Crystal Layers in Antimony‐based films

In this work we fabricate 2D Photonic crystals layers (2D‐PCL) in antimony‐based films using Holographic Lithography. The antimony‐based films present high refractive indexes that can be varied from 1.8 to 2.4, depending on the film composition, thus they are interesting materials for fabrication of 2D‐PCL. Taking into account the geometry of the fabricated structures, the band diagrams and gap maps were calculated using 2D Finite Elements Method. By measuring the transmittance as a function of the wavelength for several angles symmetry of the 2D‐PCL, it is possible to obtain the experimental band diagram. The experimental results are in good agreement with theoretical calculations of band diagram of the structure.

Photoresist absorption effect in holographic recording

In this paper we compare the photoresist profile of holographic gratings recorded using two different wavelengths λ = 458 nm and λ = 407 nm. We show that the use of the wavelength λ = 458 nm allows the recording of very deep structures (aspect ratios of >3) because for photoresist films up to 1 μm of thickness the absorption is negligible. By the other side for the wavelength λ = 407 nm the absorption coefficient increases by a factor 5. This effect reduces the inclination of lateral walls of the structures as well as disturbs our fringe locker system that uses the residual real time modulation of the refractive index of the photoresist to monitor the fringe perturbation.

Infinite 2D Photonic Crystals for the Near Infrared

In this work we propose and demonstrate a simple holographic technique that allows the fabrication of