A photoplethysmographic (PPG) device is disclosed. The PPG device can include one or more light emitters and one or more light sensors to generate the multiple light paths for measuring a PPG signal and perfusion indices of a user. The multiple light paths between each pair of light emitters and light detectors can include different separation distances to generate both an accurate PPG signal and a perfusion index value to accommodate a variety of users and usage conditions. In some examples, the multiple light paths can include the same separation distances for noise cancellation due to artifacts resulting from, for example, tilt and/or pull of the device, a user's hair, a user's skin pigmentation, and/or motion. The PPG device can further include one or more lenses and/or reflectors to increase the signal strength and/or and to obscure the optical components and associated wiring from being visible to a user's eye.

A system is described that combines spectropolarimetry with scatterometry. The system uses an annular mirror and liquid crystal devices to control the angle of the incident light cone, the polarization and wavelength, an imaging setup and one or more video cameras so that spectroseopic-polarimetric-scatterometric images can be grabbed rapidly. The system is also designed to incorporate additional imaging modes such as interference, phase contrast, fluorescence and Raman spectropolarimetric imaging.

Novel systems and methods for performing treatment (e.g., coloration) of keratinous fibers are disclosed. The methods and systems utilize one or more of a dispensing device which is configured to provide customized composition for treating keratinous fibers (e.g., a coloring composition), optionally formed from tablets; an optical reader, for obtaining sufficient characteristics of the keratinous fibers to make a realistic prediction of the outcome of a treatment (e.g., coloring treatment); a computational units for predicting an outcome of a treatment, optionally being interfaced with the dispensing device and for selecting a customized treatment; and tablet formulations which are useful in preparing customized composition for treating keratinous fibers. Further disclosed are rapidly disintegrating tablets for use in the preparation of compositions for treating keratinous fibers.

A versatile method(s) capable of reducing the time required for measurement of reflection characteristics and the amount of data indicating measurement results is (are) provided herein. An information processing apparatus may determine a measurement condition to measure reflection characteristics of an object which is to be used to generate a virtual image that can be obtained when a virtual object is observed from a predetermined virtual viewpoint in a virtual space where a virtual light source and virtual object are disposed. The information processing apparatus may include a path acquisition unit configured to acquire a path of light along which light emitted from the virtual light source reaches the virtual viewpoint after being reflected on the virtual object, and a determination unit configured to determine a measurement condition of the reflection characteristics corresponding to the path of light based on the path of light acquired by the path acquisition unit.

Disclosed are apparatus, kits, methods, and systems that include a radiation source configured to direct radiation to a sample; a detector configured to measure radiation from the sample; an electronic processor configured to determine information about the sample based on the measured radiation; a housing enclosing the source, the detector, and the electronic processor, the housing having a hand-held form factor; an arm configured to maintain a separation between the sample and the housing, the arm including a first end configured to connect to the housing and a second end configured to contact the sample; and a layer positioned on the second end of the arm, the layer being configured to contact the sample and to transmit at least a portion of the radiation from the sample to the detector.

Systems and methods for determining the cleanliness of a surface. Surface marking systems of the present disclosure can include a plurality of retroreflective microspheres dispersed in or dispensed on a carrier. Applicators of the present disclosure can include a container comprising the surface marking system, and a dispenser. Methods of the present disclosure can include applying the surface marking system to at least one discrete site on the surface; illuminating the at least one discrete site on the surface with visible light, after a cleaning; and detecting retroreflection emitted from the at least one discrete site on the surface in response to illuminating the at least one discrete site to determine the effectiveness of the cleaning of the surface.

A waveguide sensor system is provided. The system includes a light source and a waveguide formed from a light transmitting material. Light from the light source enters the waveguide at an input area and travels within the waveguide by total internal reflection to an analyte area and light to be analyzed travels within the waveguide from the analyte area by total internal reflection to an output area. An optical sensor is coupled to the output area and is configured to interact with the light to be analyzed. The system includes a plurality of pores located along the outer surface within the analyte area and formed in the light transmitting material of the waveguide, and the pores are configured to enhance light interaction with the analyte within the analyte area. The pores and analyte area may be protected and/or enhanced with a hydrophobic layer overlaying the pores.

A nonlinear crystal including stacked strontium tetraborate SrB.sub.4O.sub.7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency doubling stage of a laser assembly to generate laser output light having a wavelength in the range of about 180 nm to 200 nm. One or more fundamental laser beams are frequency doubled, down-converted and/or summed using one or more frequency conversion stages to generate an intermediate frequency light with a corresponding wavelength in the range of about 360 nm to 400 nm, and then the final frequency converting stage utilizes the nonlinear crystal to double the frequency of the intermediate frequency light to generate the desired laser output light at high power. Methods, inspection systems, lithography systems and cutting systems incorporating the laser assembly are also described.

A method, computer program product, and apparatus are provided for controlling components of a detection device. The device may detect turbidity of liquid with sensors such as a density sensor and/or nephelometric sensor. A light modulation pattern may reduce or eliminate interference in sensor readings. Readings may be performed during off cycles of an illumination light to reduce interference but to provide improved visibility of a tube. Dark and light sensor readings may be performed with an emitter respectively off or on to account for ambient light in subsequent readings. Readings from the density sensor and/or nephelometric sensor may be used to calculate McFarland values. The device may be zeroed based on an emitter level that results in a sensor reading satisfying a predetermined criterion.

The present disclosure includes systems and methods for calibration of an optical sensor package, including setting an initial detection threshold of a detector, gradually increasing a power level of a signal generator that is in communication with a detector to cause a detected power at the detector to exceed the initial detection threshold, storing in a memory a first power level of the signal generator at which the detected power at the detector exceeds the initial detection threshold, and adjusting the initial detection threshold of the detector to an adjusted detection threshold to include a detection buffer amount within the adjusted detection threshold.