Revistas
Revista:
SENSORS AND ACTUATORS B-CHEMICAL
ISSN:
0925-4005
Año:
2013
Vol.:
187
Págs.:
356 - 362
In this work, we implement an optical resonant sensor with high throughput capabilities to act as chemical or biosensor. We optimized the diffraction grating structures by FDTD simulations. Based on this study, we produced dielectric diffractive gratings in 1 cm(2) areas by laser interference lithography (LIL) and interrogated them with white light. The reflected single wavelength shifted with changes of the external medium's refractive index (RI), resolving variations of 7.3 x 10(-5) refractive index units (RIU). To exploit the broad active areas fabricated, we developed a custom instrument to acquire spatial maps of the resonance. We called the technique broad area resonance scan (BARS) and used it to characterize the geometric and material uniformity of the surfaces. We suggest this as an in situ practice to characterize photonic crystals and also as a method to scan highly parallelized analysis on a single chip in real time. In addition to a refractometric label-free application, we demonstrated a fluorescent-based measurement with the same readout and found state of the art sensitivities. Thus, the multimethod platform presented is able to double prove an assay with a single experiment in addition to its ability to screen large numbers of interactions using low volume of reagents. (C) 2012 Elsevier B. V. All rights reserved.
Revista:
OPTICS EXPRESS
ISSN:
1094-4087
Año:
2013
Vol.:
21
N°:
3
Págs.:
2978 - 2986
We present a novel method to fabricate low bend loss femtosecond-laser written waveguides that exploits the differential thermal stabilities of laser induced refractive index modifications. The technique consists of a two-step process; the first involves fabricating large multimode waveguides, while the second step consists of a thermal post-annealing process, which erases the outer ring of the refractive index profile, enabling single mode operation in the C-band. By using this procedure we report waveguides with sharp bends (down to 16.6 mm radius) and high (80%) normalized throughputs. This procedure was used to fabricate an efficient 3D, photonic device known as a "pupil-remapper" with negligible bend losses for the first time. The process will also allow for complex chips, based on 10's - 100's of waveguides to be realized in a compact foot print with short fabrication times. (C) 2013 Optical Society of America
Revista:
MICROELECTRONIC ENGINEERING
ISSN:
0167-9317
Año:
2012
Vol.:
98
Págs.:
672 - 675
Femtosecond laser micromachining has progressed considerably in the last decade due to the increasing interest in glass microsystems. In this work, we present a systematic study of the femtosecond laser ablation rate of soda-lime glass as a function of the deposited energy and pulse overlapping parameters. Experimental results demonstrate that the incubation effect reported by other authors can be neglected for particular process conditions and a constant ablation rate can be obtained, thus enhancing the depth control of the fabricated features. (C) 2012 Elsevier B.V. All rights reserved.
Revista:
OPTICAL MATERIALS EXPRESS
ISSN:
2159-3930
Año:
2012
Vol.:
2
N°:
11
Págs.:
1571 - 1579
Metallic gratings were fabricated using high energy laser interference lithography with a frequency tripled Nd:YAG nanosecond laser. The grating structures were first recorded in a photosensitive layer and afterwards transferred to an Au film. High quality Au gratings with a period of 770 nm and peak-to-valley heights of 20-60 nm exhibiting plasmonic resonance response were successfully designed, fabricated and characterized. (C) 2012 Optical Society of America