To discuss your project or needs in optoelectronics, non-contact measurement instrumentation or LED illumination engineering, please speak with Dan McGraw at Light Diagnostics at (801)293-9266.
We do custom design and development and prototyping as well as factory visits to brainstorm solutions to your process metrology needs.
Some of the problems addressed and our solutions are listed below.
Gas Phase Analysis
The Challenge: Design a diagnostic to measue plasma velocities and densities from the Xenon plasma thruster for the NASA Jupiter Icy Moons Orbiter Mission
Our Solution: A narrowband time correllation multispectral imaging camera to continuosly monitor singly and doubly ionized Xenon densities in the back plume and plasma velocities in the thrust plume.
The Challenge: For a proteomics start-up company, design an optical method to measure stable isotope ratios of HDO/H2O in nanogram quantities using DNA isolated from tissue biopsies to determine the rate at which cells are made in the body.
Our Solution: Invented a novel instrument: Double Differential Capillary Cavity Frequency Domain Ring-Down Spectrometer using an InGaAs diode laser to measure HDO/H2O ratios in submicrogram samples relative to a reference gas.
The Challenge: A medical device start-up needed to reduce the technical complexity/risk of their NASA developed lead-salt diode 13CO2 spectroscopy system in order to attract venture funding for the breath tesiting/liver function diagnostic.
Our Solution: A mid-IR source and cooled detection subsystem providing order of magnitude reductions in cost and size and two order-of-magnitude increase in reliability.
Blood/Liquid
The Challenge: Provide an on-line count of platelet number while maintaining low shear force conditions during apherisis.
Our Solution: Experiments showed a multi-color, multi-angle light scattering system could accurately determine platelet count independent of mean platelet size.
The Challenge: A fiber optic fluorimeter was needed to accompany a fetal blood pH monitoring catheter used during labor and delivery.
Our Solution: Designed and built a custom dual channel fluorimeter with femto-watt sensitivity. Tested and calibrated the system for pH. Delivered the device for clinical testing.
The Challenge: The lack of a diagnostic for fetal oxygen sufficiency (together with a litigios environment) had caused births by Cesaerian section to climb to 30%. Doctors estimate the less than 5% of babies are in true fetal distress during delivery.
Our Solution: Designed and developed the worlds smallest spectrometer: fits in a helical hypodermic needle that is twisted into the babys scalp, providing real-time photometric monitoring of fetal oxygen saturation. Optimized the excitation wavelengths for best accuracy and to minimize interferences from variations in tissue color, physiology, temperature and device manufacturing variations.
The Challenge: Solve Noyes' Dillemma: Measure the photo-dissociation yield of Iodine (I2) in solution.
Our Solution: Anharmonic Forced Rayleigh Scattering: A laser induced transient grating technique providing a zero background measurement of deviations from linear absorption.
Tissue
The Challenge: Make an optical system for a mid-infrared non-invasive glucose assay of the white of the eye.
Our Solution: COLIRS: Catadioptric Objective for Lambertian Infra-Red Source; a novel f/#0.12 achromatic all plastic reflective/refractive optical system allowing efficient excitation and collection of diffuse and specular scattered radiation.
The Challenge: A vitamin manufacturer wants an inexpensive non-invasive means to assay lycopene and beta-carotene in-vivo in human skin.
Our Solution: Developed a handheld, LED source resonance Raman spectrometer for quantification of carotenois in skin. Designed and fabricated ten units, calibrated and delivered with embedded computer, USB interface and design documentation.
The Challenge: A venture funded company had a $30,000 cost target for a commercial clinical prototype fluorescence imaging spectrometer that would reproduce the cervical cancer diagnosis of their million dollar lab prototype.
Our Solution: Designed the layout and did the systems analysis to predict the performance of four different source/detector configurations that would acheive a low cost/low risk alternative. Determined critical subsystem specifications required to attain target sensitivity/specificity specifications for cancer diagnosis.
The Challenge: X-ray mammography has hisensitivity to calcified tumors, but low sensitivity to soft tissue tumors.
Our Solution: Developed a technique: Optical Heterody Mammography which improves the resolution of near Infrared transilluminationtechniques and has better sensitivity to scattering by small gradients in tissue density than X-ray.
Solids
The Challenge: Develop a local probe of photo-carrier dynamics for use during semiconductor processing.
Our Solution: Grating Excitaton Luminescence Upconversion Microscopy: a pico-second time-resolved and micron spatially resolved probe of photocarrier diffusion and recombination.
The Challenge: Access the potensial of polysilanes for use in ultrafast optical switching and harmonic generation.
Our Solution: Polarization Resolved Optical Phase Conjugation: a technique for resolving the nuclear and electronic contributions to the optical nonlinearity.
The Challenge: Measure weak absorptions (0.0001%) in transluscent materials.
Our Solution: First demonstration of self-pumped phase conjugation in Barium Titanate as an optical novelty filter for transient absorption induce thermal abberations, setting the record for weakest absorptions detected in translucent materials.
Dimensional
The Challenge: Eliminate "ghost images" in an optical guidance system used for coronary angioplasty.
Our Solution: Analysed results of the super-luminescent diode, fiber interferometer, fiber catheter system. Identified and reccommended changing one parameter out of 25 to eliminate the "ghost images".
The Challenge: The existing "flying caliper" means of measuring paper thichness on the fly is inadequate for recycled pulp because residue buildup causes paper tears, which shuts down the mill.
Our Solution: Designed a novel non-contact measurement of measuring paper thickness using optical diffusion projection, which compensates for gradients in paper density and fiber anisotropy.
The Challenge: No method to measure the shape of strongly aspericla surfaces.
Our Solution: Invented new Interferometric Zonal Test data inversion algorithm which measures with sub-micron accuracy speres which deviate more than 100 microns from a best fit sphere.
The Challenge: New molded glass lenses have a different distribution of surface defects than ground and polished lenses:they have the correct curvature but have a fine surface roughness.
Our Solution: Developed new lens production process metrology: An automated blue laser scatterometer provided an objective measure of surface roughness tied to picture quality while improving lens manufacture and test throughput by an order of magnitude.
Light Sources
The Challenge: A major maker of equipment for blood banks needed to optimise the photo-reaction conditions to efficiently inactivate viruses in whole blood.
Our Solution: Blood lab measurements and a literature review indicated a two-step, two-photon photo-raction was occurring. We determined an optimum two-color excitation spectrum accounting for the prescence of overlapping hemoglobin and sensitizer absorption. identified and optimized light sources and purchased spectroscopic instrumentation for the further study of the photo-raction kinetics.
The Challenge: An ophthalmic device startup company wanted to market the first laser based system for cataract removal.
Our Solution: Built and tested five solid state lamp-pumped lasers to determine optimum wavelength, pulse duration, and repetition rate. Compare light scatter and pressure shock-wave measuremnts with standard ritinal damage thresholds to determine safe system specifications for the laser and laser surgical hand piece.
The Challenge: Develop an efficient solid state source of pico-second pulsed blue light.
Our Solution: Parametric Mode Locking: Active and passive mode locking methods using intracavity sum frequency generation to simultaneously upconvert to blue and mode lock the system. Patented and demonstrated with a Nd:YAG laser system.
The Challenge: Field fluorescence observations have high sensitivity but poor specificity, limiting their applicability.
Our Solution: Fluorescence Excitation Ratiometry: a field portable fluorescence viewing system that provides a quantitative, differential measurement, greatly increasing the specificity of field fluorescence observations.
