System and apparatus for portable gas detection. Specifically, this disclosure describes apparatuses and systems for optical gas detection in a compact package. There is a need for a very compact, low-power, gas detection system for gases such as CO2, NOx, water vapor, methane etc. This disclosure provides an ultra-compact and highly efficient optical measurement system based on principals of optical absorption spectroscopy. It reduces the size of the instrument as well its power consumption by more than an order of magnitude making it possible to deploy it widely. There is an identified need for large number of distributed gas sensors to improve human health, environment, and save energy usage.

A device for measuring oxygen saturation includes circuitry configured to measure a first diode voltage at a light emitting diode while applying a first current through the light emitting diode, measure a second diode voltage at the light emitting diode while applying a second current through the light emitting diode, and measure a third diode voltage at a light emitting diode while applying a third current through the light emitting diode. The circuitry is further configured to determine a series resistance based on the first diode voltage, the second diode voltage, and the third diode voltage and determine an intensity of a received photonic signal corresponding to an output photonic signal output using the light emitting diode. The circuitry is further configured to determine an oxygen saturation level based on the intensity of the received photonic signal and the series resistance.

A laser sensor includes: a receiver array configured to convert received optical signals into electrical signals, wherein a noise floor of the electrical signals is positively correlated with temperature if environmental temperature is within a first preset temperature range, and negatively correlated with the temperature if the environmental temperature is within a second preset temperature range; a compensation module coupled with the receiver array and configured to receive the electrical signals, amplify the electrical signals with a first and a second amplification factors, respectively, when the environmental temperature is within the first and the second preset temperature ranges, wherein the first amplification factor is negatively correlated with the temperature and the second amplification factor is positively correlated with the temperature; and a processor coupled with the compensation module and configured to identify sensing signals based on the electrical signals amplified by the compensation module and the noise floor.

The present application relates to the measurement technology of the homogeneity in optical materials, and more particularly to a method for evaluating and controlling temperature influence on a homogeneity test for infrared optical materials. The precision of the test results is found to be affected by local small temperature changes of the sample during the homogeneity test for the refractive indexes of infrared optical materials, the invention establishes a two-dimensional numerical table in which the test precision requirements of a refractive index homogeneity test for infrared optical materials correspond to the ambient control temperatures in the test room corresponding to the influence of temperature changes on the refractive index of different infrared optical materials. In addition, related calculation formulas are established for theory analysis, numerical calculation and form-designing. The method of the present invention accurately guides the temperature control for the precision of the homogeneity test for infrared optical materials.

The present application relates to the measurement technology of the homogeneity in optical materials, and more particularly to a method for evaluating and controlling temperature influence on a homogeneity test for infrared optical materials. The precision of the test results is found to be affected by local small temperature changes of the sample during the homogeneity test for the refractive indexes of infrared optical materials, the invention establishes a two-dimensional numerical table in which the test precision requirements of a refractive index homogeneity test for infrared optical materials correspond to the ambient control temperatures in the test room corresponding to the influence of temperature changes on the refractive index of different infrared optical materials. In addition, related calculation formulas are established for theory analysis, numerical calculation and form-designing. The method of the present invention accurately guides the temperature control for the precision of the homogeneity test for infrared optical materials.

The present invention provides a wide-area sample-based reader design which serves as a diagnostic detection device for bio-particles.

An aquatic environment water parameter testing method that utilizes the conductivity of a liquid sample of an aquatic environment to correct an optical reading of a chemical indicator that has been exposed to the liquid sample to determine the level of a constituent in the aquatic environment. The conductivity of the liquid sample is determined, the chemical indicator element is exposed to the liquid sample, an optical reading is measured from the chemical indicator, and the optical reading is corrected using the conductivity. The temperature of the liquid sample may be utilized to correct the conductivity prior to correcting the optical reading. The temperature of an optical reader used to measure the optical reading may be utilized to correct the optical reading.

An optical measurement method and system. The system includes, and method applies, a light source, a beamsplitter, at least one filter, a output photodetector for acquiring data of a sample, and a correction photodetector for correcting and maintaining output intensity from the light source. The filter is located between the light source and the correction photodetector for normalizing the spectrum of the input light being applied to input light correction. The filter may be incorporated into the beamsplitter and may be tuned to filter light from the light source for providing non-zero transmission of light with a near-zero gradient for wavelengths in a portion of the spectrum of the input light being applied to the sample and read by the output photodetector. The filter may also or alternatively be located downstream of the beamsplitter to correct for wavelength sensitivity of the correction photodetector.

The present application describes an optical sensor for measuring oxygen gas levels in a medium. The optical sensor includes a substrate having a first and second surface. The optical sensor also includes a first coating applied on the first surface of the substrate. The first coating may include an oxygen impermeable matrix doped with a first fluorophore. The optical sensor may include a second coating applied on the substrate. The present application also describes a capnography system for measuring oxygen including an optical sensor and an algorithm to estimate the maxima of oxygen levels from instantaneous oxygen levels and calculating instantaneous carbon dioxide levels from the difference between average maximum oxygen gas level and instantaneous oxygen gas level.

A device for optical detection of analytes in a sample includes at least two optoelectronic components. The optoelectronic components include at least one optical detector configured to receive a photon and at least one optical emitter configured to emit a photon. The at least one optical emitter includes at least three optical emitters disposed in a flat, non-linear arrangement, and the at least one optical detector includes at least three optical detectors disposed in a flat, non-linear arrangement. The at least three optical emitters and the at least three optical detectors include at least three different wavelength characteristics.