Compact optical sources and methods for producing short and ultrashort optical pulses are described. A semiconductor laser or LED may be driven with a bipolar waveform to generate optical pulses with FWHM durations as short as approximately 85 ps having suppressed tail emission. The pulsed optical sources may be used for fluorescent lifetime analysis of biological samples and time-of-flight imaging, among other applications.

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.

Systems and methods for analysis of samples, and in certain embodiments, microfluidic sample analyzers configured to receive a cassette containing a sample therein to perform an analysis of the sample are described. The microfluidic sample analyzers may be used to control fluid flow, mixing, and sample analysis in a variety of microfluidic systems such as microfluidic point-of-care diagnostic platforms. Advantageously, the microfluidic sample analyzers may be, in some embodiments, inexpensive, reduced in size compared to conventional bench top systems, and simple to use. Cassettes that can operate with the sample analyzers are also described.

A external accessory can allow a mobile device to perform microscopy imaging with Type-C ultraviolet (UVC) light excitation. The external accessory includes a compound lens placed in front of a camera lens of the mobile device. A light transparent optical window configured to be placed in front of the compound lens and positioned such that a front surface of the optical window overlaps the front focal plane of the compound lens. One or more light emitting diode (LED) that emits UVC light positioned at one or more side-edges of the optical window. The one or more LED emits UVC light through the optical window so that the UVC light undergoes total internal reflection. An externally triggered LED driver configured to power and control the LED(s).

Described herein are methods for imaging a fluorescent bioassay (including a substrate, such as dispersed cellular sample, exposed to one or more exogenous fluorophore and/or fluorescent probe that accumulate in a structure of interest). The bioassay can be excited with Type-C ultraviolet (UVC) light produced by one or more light emitting diode (LED). The UVC can have a center wavelength that causes emission by the fluorescent bioassay. A digital optical device can collect a signal emitted from the fluorescent bioassay in response to the excitation. The methods relate in particular to Microscopy with Ultraviolet Surface Excitation (MUSE) imaging.

A micro-colorimetric sensor for sensing target chemicals using edge tracking includes a substrate. A plurality of parallel linear channels of porous media is entrenched into the substrate and each linear channel includes a sensing material adapted to sense one of several specific target chemicals in air. The plurality of parallel linear channels is separated by barrier material from the adjacent parallel linear channel where the barrier material blocks diffusion of chemicals from one linear channel to another. A plate is affixed over the substrate top to cover the plurality of parallel linear channels. An air sample is diffused along the micro-colorimetric sensor and color images are captured. An intensity profile is derived from the plurality of color images to determine a maximum and a minimum intensity value along the sensor. A plurality of positions along the sensor is tracked to determine an edge position.

A system for detecting signal components of light induced by multiple excitation sources including: a flow channel including at least two spatially separated optical interrogation zones; a non-modulating excitation source that directs a light beam of a first wavelength at a near constant intensity onto a first of the optical interrogation zones; a modulating excitation source that directs a light beam of a second wavelength with an intensity modulated over time at a modulating frequency onto a second of the optical interrogation zones; a detector subsystem comprising a set of detectors configured to detect light emitted from particles flowing through the at least two optical interrogation zones and to convert the detected light into a total electrical signal; and a processor that determines signal components from the light detected from each of the optical interrogation zones.

A micro-colorimetric sensor for sensing target chemicals that converts time sequence information into a spatial distribution of color. By tracking the spatial color distribution, chemical exposure over time is thus detected, which overcomes the limitation of traditional colorimetric sensors. A porous media is coated on a top surface of the substrate. Multiple sensing chemicals are fused in parallel linear channels into the porous media coating. A plate is affixed over the substrate top surface to cover the plurality of parallel linear channels. An air sample is diffused along the porous media to get a clear pattern of spatial color distribution and color images are captured. Optical parameters like gradient of spatial color distribution, intensity, and absorbance, etc., can be tracked to calculate analytes concentrations.

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.

A compact optical imaging system including a single filter and a light source that provides lateral illumination for bead detection in digital assays. The light source is configured to emit light toward the detection vessel. The single filter is positioned to receive light reflected from a sample in the detection vessel, that originated from the light source, and receive an output from a sample in the detection vessel. A detector is configured to receive a portion of the reflected light and a portion of the output that passes through the single filter.