Integrated opto-chemical sensors

Integrated opto-chemical sensors have promising prospects, for example by having the potential to be realized as very sensitive small monolithic smart multisensor systems with a digital signal output. Here the main accent will be laid on the optical principles underlying chemo-optical waveguiding sensors, focusing on linear evanescent field sensors. Sensing principles and systems based on interferometry, surface plasmon resonance and luminescence quenching will be treated in more detail. Materials and technologies applied to integrated optic sensors are mentioned

Passive polarization converter in SiON technology

A passive polarization converter has been realized in silicon oxynitride (SiON) technology. The device is a grating assisted codirectional coupler consisting of segments of asymmetrically etched ridge waveguides. By using a double-masking technique, the fabrication of the device is tolerant with respect to the alignment of the required masks. Conversion efficiencies up to 0.98 (TE¿TM and TM¿TE) and insertion losses of 3 dB/cm have been measured. Using 2-D beam propagation method simulations, an observed beat pattern in the converter could be explained as due to a leaky mode, which is captured in the grating structur

Chemo-optical microsensing systems

Chemo-optical microsensing systems, whether based on fiber optics or integrated optics, show promising prospects. The physical principles underlying chemo-optical waveguide sensors are discussed with the accent on linear evanescent field sensors. The role of the chemo-optical transduction layer is emphasized. Restriction of the freedom of design by technological uncertainties is briefly dealt with. The structure of a complete micro-sensing system is discussed and illustrated by presenting various design of chemo-optical sensors based on surface plasmon resonance

A new method for the calculation of propagation constants and field profiles of guided modes of nonlinear channel waveguides based on the effective index method

In this paper, an extension of the effective index method (EIM) to waveguiding structures containing ideal or saturable third-order nonlinear materials is presented. By applying separation of variables to the dominant field component, the complete problem is subdivided into two scalar problems in the lateral and transverse direction, as in the case of the normal EIM. Making use of the strong transverse confinement, as observed in most real waveguide structures, the nonlinear index changes of the various transverse sections can be lumped into nonlinear effective indexes of the equivalent layered planar structures. By using these nonlinear effective indexes in self-consistent field calculations in the transverse direction, a complete approximate solution is obtained. In this way, the amount of computational effort required for the calculation of the effective indexes and field profiles of the waveguides can be reduced significantl

Silicon oxynitride in integrated optics

A review on the state of the art of silicon oxynitride deposition at the MESA Research Institute will be given. The recent progress in the application of silicon oxynitride in communication devices will be discusse

Realization and Characterization of a Four-Channel Integrated Optical Young Interferometer

In this paper, we report the realization and characterization of a four-channel integrated optical Young interferometer (YI), which enables simultaneous and independent monitoring of three binding processes. The simultaneous and independent measurement of three different glucose concentrations shows the multi-purpose feature of such device. The phase resolution for different pairs of channels was /spl sim/1/spl times/10/sup -4/ fringes, which corresponds to a refractive index resolution of /spl sim/8.5/spl times/10/sup -8/ . The observed errors, which are caused due to mismatching of spatial frequencies of individual interference patterns with those determined from the CCD camera, have been reduced by using different reduction schemes. In addition, we have investigated a novel method for discrimination of the refractive index change from the thickness of a bound layer during an immunoreaction, as well as measuring the temperature change the takes place during such a process

Luminescent thin films by the chemical aerosol deposition technology (CADT)

Zinc sulphide thin films have been deposited with CART using zinc chlorideand zinc acetylacetonate as Zn compounds and thiourea and 1,1,3,3-tetramethylthiourea as S compounds soluted in methanol, ethanol, isopropanol and cellosolve. After optimalization of the deposition process homogeneous layers with a c-axis oriented hexagonal columnar structure with a high density (up to 96%) were obtained. Luminescence was observed with films grown above 500°C. The influence of the hot plate temperature, flow of carrier gas, nozzle geometry, distance nozzle substrate, and volatility of the solvent and reactants on the growth rate, homogenity and density of the film has been shown. Some rules for the selection of the starting compound are given. TG analyses of the reactant compounds was used to compare their volatility and stability

Birefringence compensation in double-core optical waveguides

A new concept for birefringence compensation in planar optical waveguides applying a double-core structure is introduced. It is demonstrated on waveguides fabricated in silicon oxynitride technology for applications in optical telecommunicatio