An apparatus includes an optical emitter configured to emit a first optical signal along an optical path towards a target object in an outdoor environment. The apparatus includes an optical detector positioned collinearly with respect to the optical emitter. The optical detector is configured to detect a second optical signal that is retro-reflected from the target object. The apparatus includes a lock-in amplifier coupled to the optical detector. The lock-in amplifier is configured to generate, based on the first optical signal and the second optical signal, a signal indicative of a retro-reflectivity of the target object in the outdoor environment.

Various embodiments include methods and scanning systems for photonically detecting an object of high-interest having selective wavelength reflection. Various embodiments include sequentially scanning the environment by projecting a non-coherent pulsed electromagnetic beam of light of a first wavelength. Reflected light of the first non-coherent beam is received onto a photoelectric detector, which outputs digital intensity data. Various embodiments further include sequentially scanning the environment by projecting a non-coherent pulsed electromagnetic beam of light of a second wavelength different from the first wavelength. Reflected light of the second non-coherent beam is received onto a photoelectric detector, which outputs digital intensity data. The intensity of the reflected light of the first wavelength may be compared with the intensity reflected light of the second wavelength, and an alert may be sent to an autonomous vehicle system in response to the intensity difference exceeding a threshold.

Apparatuses and methods for monitoring curing of photocurable material are disclosed. The methods generally include directing an ultraviolet cure light into a photocurable material, wherein the ultraviolet cure light causes the photocurable material to cure; directing a probe light into the photocurable material through an optical fiber during the cure; collecting a back reflection signal from the photocurable material with the optical fiber; and determining a refractive index change of the photocurable material during the cure.

An optical gene biosensor is disclosed. The optical gene biosensor includes a substrate; a molecular beacon anchored to the substrate, wherein the molecular beacon includes an oligonucleotide specifically binding to a target nucleic acid molecule and a first compound bound to a first terminal of the oligonucleotide; an optical marker specifically binding to the first compound, wherein the optical marker is configured to retro-reflect irradiated light; a light source for irradiating the optical marker with light; and a light-receiver for receiving light retro-reflected from the optical marker. The optical gene biosensor may perform accurate quantitative analysis of a target nucleic acid molecule using both non-spectral and spectral light sources.

Disclosed is a retroreflector-based sensor system for optical characterization of a sample, having a transmitter for irradiating the sample, a retroflector positioned behind the sample, the transmitter, the sample, and the retroreflector being positioned such that radiation reflected back from the retroreflector is again incident on the sample and is reflected back from the latter in the direction towards the transmitter, and a receiver which is positioned in the receiving beam path such that it detects radiation reflected back from the retroreflector, incident again on the sample and reflected back from the latter, in the direction towards the transmitter.

A device comprising an imaging unit for capturing an image of a target object and of an accessory. The accessory comprises a reference target object having a known retroreflective coefficient. The device also comprises a calculating unit for calculating a value of a retroreflective coefficient of the target object based on a comparison of the image of the target to the image of the accessory.

The method of the invention comprises: obtaining a sequence of at least two images, with different levels of illumination; extracting the region containing the sign in the image; calculating the luminance values of the signs; and obtaining the difference in luminance of the sign corresponding to the two levels of illumination. The value obtained is the luminance of the sign (11) corresponding to an illumination equal to the difference between the illuminations, or additional illumination. This result is based on the additive property of luminance, according to which the luminance of a sign is the sum of the luminance produced by each source of illumination. A basic illumination device (5), an additional illumination device (7), at least one camera for taking images, and image recording, positioning and synchronism systems are required to implement the method.

The method of the invention comprises: obtaining a sequence of at least two images, with different levels of illumination; extracting the region containing the sign in the image; calculating the luminance values of the signs; and obtaining the difference in luminance of the sign corresponding to the two levels of illumination. The value obtained is the luminance of the sign (11) corresponding to an illumination equal to the difference between the illuminations, or additional illumination. This result is based on the additive property of luminance, according to which the luminance of a sign is the sum of the luminance produced by each source of illumination. A basic illumination device (5), an additional illumination device (7), at least one camera for taking images, and image recording, positioning and synchronism systems are required to implement the method.

A system for measuring the reflectivity of a painted object includes an electromagnetic wave source that emits an electromagnetic wave, a panel that holds the painted object, with the panel being movable to adjust an incident angle of the electromagnetic wave onto the panel, a reflector to receive and direct electromagnetic waves that are reflected by the painted object towards the reflector, a detector to detect an intensity of electromagnetic waves, and a control unit. The control unit is communicatively connected to the panel and to the detector. The control unit determines the incident angle of the electromagnetic wave, receives the intensity of the electromagnetic wave detected by the detector, and determines the reflectivity of the painted object as a function of the intensity of the electromagnetic wave detected by the detector over a predetermined range of incident angle values.

A system for measuring the reflectivity of a painted object includes an electromagnetic wave source that emits an electromagnetic wave, a panel that holds the painted object, with the panel being movable to adjust an incident angle of the electromagnetic wave onto the panel, a reflector to receive and direct electromagnetic waves that are reflected by the painted object towards the reflector, a detector to detect an intensity of electromagnetic waves, and a control unit. The control unit is communicatively connected to the panel and to the detector. The control unit determines the incident angle of the electromagnetic wave, receives the intensity of the electromagnetic wave detected by the detector, and determines the reflectivity of the painted object as a function of the intensity of the electromagnetic wave detected by the detector over a predetermined range of incident angle values.