Carlos F. R. Mateus

Ultrabroadband mirror using low-index cladded subwavelength grating

We report a novel subwavelength grating that has a very broad reflection spectrum and very high reflectivity. The design is scalable for different wavelengths. It facilitates monolithic integration of optoelectronic devices at a wide range of wavelengths from visible to far infrared.

Broad-band mirror (1.12-1.62 /spl mu/m) using a subwavelength grating

We report the first experimental demonstration of a novel single-layer subwavelength grating (SWG) that has >500-nm-wide reflection spectrum from 1.12-1.62 /spl mu/m and very high reflectivity (>98.5%). This SWG is scalable for different wavelengths by simply changing the grating dimensions, which, thus, facilitates monolithic integration of devices over a wide range of wavelengths.

Widely tunable torsional optical filter

A broad range tunable optical filter using a torsional micromechanical structure is presented. The device has a continuous tuning range over 100 nm, from 1500 to 1600 nm, and the structure eliminates the potential catastrophic discharge problem associated with electrostatic micromachines. Transmission of a 2.5-Gb/s directly modulated 1550-nm vertical-cavity surface-emitting laser through the tunable filter shows no power penalty.

Fabrication and design of an integrable subwavelength ultrabroadband dielectric mirror

We have designed and fabricated a subwavelength grating (SWG) broadband mirror whose performance depends on key factors, including SWG period, duty cycle, and angle of incident light. The fabricated SWGs exhibit high reflectivity (⩾96%), when the grating periods are varied from 650to750nm and duty cycles are varied from 55% to 65%. The bandwidth and reflectivity of these mirrors are remarkably robust to variations in design and fabrication. The SWGs can be designed as broadband mirrors from microwave to visible wavelengths.

Compact label-free biosensor using VCSEL-based measurement system

We report an ultracompact label-free biosensor that uses a vertical-cavity surface-emitting laser (VCSEL)-based measurement system for the characterization of biomolecular interactions. It consists of a VCSEL, a plastic guided-mode resonant filter, and two p-i-n detectors. The system has demonstrated very high sensitivity to molecules on top of the sensor.

VCSEL Optoelectronic Biosensor for Detection of Infectious Diseases

We report on the detection of human anti-dengue antibodies from serum samples using a compact optoelectronic label-free biosensor. The system consists of a tunable vertical-cavity surface-emitting laser, guided-mode resonant sensor surface, and two silicon pin detectors. This novel biosensor demonstrated sufficient sensitivity in a clinical-relevant assay, making it a potential new platform for simplified and rapid point-of-care diagnostic tests for the detection of infectious diseases.

Ultracompact high-sensitivity label-free biosensor using VCSEL

We report a new label-free biosensor system for protein interaction characterization. The system consists of a VCSEL, a plastic guided mode resonant filter, and a pin detector. The sensor has high sensitivity and ultra compactness, consumes low power, and can be fabricated in 2D arrays.

Design of ultra-wide continuously tunable optical filter using sub-wavelength grating reflectors

We propose the design of a widely tunable optical filter consisting of two cascaded sub-wavelength grating mirrors with a variable air gap. The device is scalable to far-infrared wavelengths and requires a low actuation voltage.

General design rules for MEMS tunable optical filters

Summary from only given. Tunable optical filters are important for applications such as DWDM optical networks. Micromechanically actuated filters are desirable because of their wide tuning range, design flexibility and high yield. The device structure consists of epitaxial layers forming a single Fabry-Perot cavity, having two distributed Bragg reflectors (DBRs) and an air gap in-between. We recently reported >100 nm tuning around 1550 nm using a torsional structure. The purpose of this paper is to determine how scalable the various designs are and to establish the design rules. The design flow chart for a MEMS filter using deflection beams is shown.