A Miniaturized Optical Sensor with Integrated Gas Cell

The design, fabrication and characterization of a highly integrated optical gas sensor is presented. The gas cell takes up most of the space in a microspectrometer and is the only component that has so far not been miniaturized. Using the tapered resonator cavity of a linear variable optical filter as a gas cell enables ultimate miniaturization,...

Vapour HF release of airgap-based UV-visible optical filters

The design and CMOS-compatible fabrication of airgap-based optical filters in a surface micromachining process with sacrificial release using thevapour phase is presented. An airgap-dielectric layer combination offers a higher refractive index contrast, as compared to the conventional all-dielectriclayer based filters, which results in a higher...

Optical Filter for Providing the Required Illumination to Enable Narrow Band Imaging

This paper presents the design, fabrication and characterization of two Fabry Perot type optical filters (415 nm and 540 nm) for enabling Narrow Band Imaging (NBI) in medical devices (MD). The two-colour illumination should satisfy a highly specific optical design, which is composed of a thin-film optical filter stack of titanium dioxide (TiO2)...

A Lossy Fabry-perot Based Optical Filter for Natural Gas Analysis

A set-up for optical gas composition measurement based on absorption spectroscopy is composed of a white light source, a gas cell and a spectrometer. The Fabry-Perot optical filter is suitable for miniaturization of this system, as it is composed of only two reflectors with a transparent layer in-between. Varying the width of this optical...

IR Microspectrometers based on Linear-Variable Optical Filters

This paper presents the design, fabrication and characterization of Infra-Red (IR) Linear Variable Optical Filter (LVOF)-based micro-spectrometers. Two LVOF microspectrometer designs have been realized: one for operating in the 1400 nm to 2500 nm wavelength range and another between 3000 nm and 5000 nm. The IR LVOFs have been fabricated in an IC...

An UV linear variable optical filter-based micro-spectrometer

This paper presents the design, fabrication and spectral measurements of an Ultra-Violet (UV) Linear Variable Optical Filter (LVOF)-based micro-spectrometer operating in the 300 nm–400 nm wavelength range. The UV LVOF has been fabricated in an IC-Compatible process using resist reflow. Characterization by passing monochromatic light through the...

Spectral measurement with a linear variable filter using a LMS algorithm

This paper presents spectral measurements using a linear variable optical filter. A LVOF has been developed for operation in the 530 nm–720 nm spectral band and has been fabricated in an IC-compatible process. The LVOF has been mounted on a CMOS camera. A Least Mean Square algorithm has been implemented to calculate the spectrum of light from...

Spectral measurement using IC-compatible linear variable optical filter

This paper reports on the functional and spectral characterization of a microspectrometer based on a CMOS detector array covered by an IC-Compatible Linear Variable Optical Filter (LVOF). The Fabry-Perot LVOF is composed of 15 dielectric layers with a tapered middle cavity layer, which has been fabricated in an IC-Compatible process using resist...

CMOS-compatible LVOF-based visible microspectrometer

This paper reports on a CMOS-Compatible Linear Variable Optical Filter (LVOF) visible micro-spectrometer. The CMOS-compatible post process for fabrication of the LVOF has been used for integration of the LVOF with a CMOS chip containing a 128-element photodiode array and readout circuitry. Fabrication of LVOF involves a process for fabrication...