In order to distinguish between a deterioration in a received optical signal strength resulting from optical axis deviation, and a deterioration in the received optical signal strength due to the effects of dust and the like, this detecting system is provided with: a transmitter provided with a light emitting unit for transmitting a first optical signal and a second optical signal having mutually different wavelengths and divergence angles; and a receiver provided with a detecting unit for receiving the first and second optical signals and outputting a first reception signal indicating the reception strength of the first optical signal, and a second reception signal indicating the reception strength of the second optical signal, and an identification unit for determining a state of propagation of the first and second optical signals on the basis of an amount of variation in the first and second reception signals.

Device for improving an optical detecting smoke apparatus and implementing thereof. Apparatus and methods for detecting the presence of smoke in a small, long-lasting smoke detector are disclosed. Specifically, the present disclosure shows how to build one or more optimized blocking members in a smoke detector to augment signal to noise ratio. This is performed while keeping the reflections from the housing structure to a very low value while satisfying all the other peripheral needs of fast response to smoke and preventing ambient light. This allows very small measurements of light scattering of the smoke particles to be reliable in a device resistant to the negative effects of dust. In particular, geometrical optical elements, e.g., cap and optical defection elements, are disclosed.

An imaging system for measuring water and blood lipid content in a tissue sample includes a light source configured to emit a plurality of sequential wavelengths of light within a predetermined range of wavelengths, a spatial modulation device configured to direct each of the plurality of sequential wavelengths of light onto a tissue sample plane to generate a first plurality of patterns on the issue sample plane at a first spatial frequency and a second plurality of patterns on the tissue sample plane at a second spatial frequency, an imaging device configured to generate first image data reproducible as images the first plurality of patterns and second image data reproducible as images the second plurality of patterns, and a controller configured to determine a first optical property and a second optical property for each location on the sample plane.

In a method and apparatus, a property of an optically diffuse medium including a first optical absorber having a first concentration and a second optical absorber having a second concentration is determined. A surface area of the medium is imaged at multiple wavelengths around an isosbestic wavelength of the first absorber and the second absorber. A reflectance spectrum of the medium at the surface area at the multiple wavelengths is determined. A derivative of the determined reflectance spectrum around the isosbestic wavelength is determined. From the derivative, a concentration ratio of the first concentration and the second concentration is estimated.

In order to distinguish between a deterioration in a received optical signal strength resulting from optical axis deviation, and a deterioration in the received optical signal strength due to the effects of dust and the like, this detecting system is provided with: a transmitter provided with a light emitting unit for transmitting a first optical signal and a second optical signal having mutually different wavelengths and divergence angles; and a receiver provided with a detecting unit for receiving the first and second optical signals and outputting a first reception signal indicating the reception strength of the first optical signal, and a second reception signal indicating the reception strength of the second optical signal, and an identification unit for determining a state of propagation of the first and second optical signals on the basis of an amount of variation in the first and second reception signals.

Systems and methods for detecting trace gases utilize a resonance optical cavity and one, two or more coherent light sources coupled to the cavity through one or more cavity coupling mirrors, whereby two or more optical cavities may share the same gas volume.

According to an embodiment, an optical inspection apparatus includes: an illumination portion, a wavelength selection portion and an imaging portion. The illumination portion irradiates a first object point of a surface of an object with first illumination light, and a second object point of the surface of the object with second illumination light. The imaging portion images light from the first object point through the wavelength selection portion when a normal direction at the first object point and a direction of the first illumination light have an opposing relationship, and images light from the second object point through the wavelength selection portion when a normal direction at the second object point and a direction of the second illumination light have an opposing relationship.

A calibration curve setting method used at the time of quantitatively analyzing specific components in a drug by a transmission Raman spectrum, the method comprising the steps of: obtaining respective transmission Raman spectra of a plurality of different wave number ranges including Raman hands corresponding to the specific components of a plurality of known drugs of which concentrations or amounts of the specific components are known and the concentrations or the amounts are different from each other; calculating candidate calibration curves which are candidates for calibration curves used for the quantitative analysis respectively from a plurality of transmission. Raman spectra in each of the wave number ranges; and using the most probable candidate calibration curve as a calibration curve for the quantitative analysis of the specific components, among the respective candidate calibration curves.

The invention relates to a portable device (1) for estimating at least one parameter characteristic of a polymer material, characterized in that the device comprises at least one infrared source (101), each infrared source (101) being capable of emitting towards the polymer material a spectral line, representing maximum emission energy, selected in one of the wavelengths 10 m, 9.5 m, 7.2 m, 6 m, 3.5 m, 2.7 m or in one of the wave numbers 1000 cm.sup.1, 1050 cm.sup.1, 1350 cm.sup.1, 1700 cm.sup.1, 2900 cm.sup.1, 3700 cm.sup.1, at least one infrared detector (102), capable of receiving infrared radiation (112), which is reflected by the polymer material (M) in response to the spectral line, a unit for determining the parameter characteristic of the polymer material (M) as a function of the energy present in said spectral line in the infrared radiation (112), having been reflected by the polymer material (M) and having been received by the infrared detector (102).

A method of performing spectroscopic measurements provides an optical frequency comb, and directs the comb through or at a sample. The optical frequency comb is generated by gain switching a laser diode constructed from Gallium Nitride and related materials. Various techniques are described for manipulating the comb source to achieve desired benefits for spectroscopy.