An optical filter including filter regions arrayed two-dimensionally, in which the filter regions include a first region and a second region; a wavelength distribution of an optical transmittance of the first region has a first local maximum in a first wavelength band and a second local maximum in a second wavelength band that differs from the first wavelength band, and a wavelength distribution of an optical transmittance of the second region has a third local maximum in a third wavelength band that differs from each of the first wavelength band and the second wavelength band and a fourth local maximum in a fourth wavelength band that differs from the third wavelength band.

A high-sensitivity nanosecond to millisecond transient absorption spectrometer for measurements of miniscule signals under low excitation intensities includes an excitation source generating a frequency greater than 100 Hz, pulsewidth less than 5 ns excitation pulse for exciting a light absorbing sample, a probe light source for generating a photon flux probe light beam producing an average irradiance greater than 1 μW m.sup.−2 nm.sup.−1 for measuring the transient absorption spectrum of the sample before and after excitation by the excitation source, a DC-coupled detector capable of measuring light for enabling synchronous measurement of both the transmission of the probe light beam and the change in transmission of the probe light beam between a signal with the excitation pulse present and a signal in the absence of the excitation pulse, and a digital oscilloscope with a trigger rearm time capable of collecting every trigger event at high frequencies including 1 MHz, for enabling sequential noise subtraction protocols.

A system for providing optical measurements and detection in optical spectrum analyzers (OSAs) with high dynamic range and high speed is disclosed. The system may include a slit to allow inward passage of an optical beam. The system may also include an optical portion to receive the optical beam. In some examples, the optical portion may include at least one optical splitter to split the optical beam into at least two optical paths. The system may also include an electrical portion to receive the optical beams split into the at least two optical paths. In some examples, the electrical portion may include at least one photodetector to receive each of the split optical beam. The electrical portion may also include at least one amplifier communicatively coupled to each of the at least one photodetector to amplify the split optical beam. The electrical portion may further include at least one analog-to-digital converter (ADC) communicatively coupled to each of the at least one amplifier to convert the split optical beams into digital signals.

A photonic integrated circuit (PIC) spectrometer for sensing the spectroscopic signature of airborne molecules, comprising a dispersive element to separate the spectral information spatially, and a tuning mechanism for said dispersive element to convert the spectral information to time-dependent information. The approach allows the PIC spectrometer to have a single (or a few) output pin(s), enabling sensing of the environment with a simple packaged chip that is compact, lightweight, energy efficient and low cost, making it suitable for platforms that have a small form factor, a small power budget, and are cost sensitive, such as mobile devices.

The invention provides systems for characterizing a biological sample by analyzing emission of fluorescent light from the biological sample upon excitation and methods for using the same. The system includes a laser source, collection fibers, a demultiplexer and an optical delay device. All references cited herein are incorporated by reference in their entirety as though fully set forth. Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Systems and methods for time-resolved spectroscopy. Exemplary methods include: providing first light and second light using an excitation source; receiving first scattered light from a material responsive to the providing the first light; signaling the detector, after a delay, to provide a first spectrum of the received first scattered light; receiving second scattered light from the material responsive to the providing the second light; signaling the detector, after the delay, to provide a second spectrum of the received second scattered light; recovering a spectrum of the material using the first spectrum and the second spectrum; and identifying at least one molecule of the material using the recovered spectrum and a database of identified spectra.

A method includes directing a first plurality of probe laser pulses through a sample, dividing each of the first plurality of probe laser pulses to generate a first interferogram, and generating first image data reproducible as a first phase image of the sample. A plurality of pump laser bursts are directed onto the sample to heat the sample. A second plurality of probe laser pulses are directed through the sample at a predetermined time delay. Each of the second plurality of probe laser pulses are divided to generate a second interferogram. Second image data is generated that is reproducible as a second phase image of the sample. A transient phase shift is determined in the second phase image relative to the first phase image. A vibrational spectroscopy property is determined of the sample based on the transient phase shift, thereby allowing an identification of chemical bond information of within the sample.

A spectroscopic apparatus includes a splitter that receives a first detected signal output from a sample to which an incident beam is irradiated, and outputs a reflected signal and a second detected signal by splitting the first detected signal, and a signal processor that receives the reflected signal and the second detected signal, and extracts a Raman signal from the second detected signal in response to the received reflected signal.

Speckle contrast method and system that discriminates photons based on their path length in tissue, the method comprising the steps of: directing light from a pulsed light into a sample by optical elements; synchronizing the time between the pulse injection to sample and the detection unit; collecting the photons that have travelled through the sample by optics, and conveying the photons of a single or a limited number of speckles from the sample to one or more detection elements; time-tagging photons thanks to the synchronization of the detector element and/or the time-tagging electronics with the laser pulse emission; estimating each photon time-of-flight by the difference between its time tag and the laser pulse emission; categorizing the detected photons based on the value of the time-of-flight in a certain number of time gates; measuring the speckle contrast.

Devices and methods for sampling an analog signal to perform data analysis are disclosed. The sampling devices and corresponding methods include a detector module that measures a response generated from a sample, an analog to digital converter that samples the analog signal, received from the detector module, and converting it into a digital signal, a sampling rate of the converter being faster than the response of the sample; and a logic circuit coupled to the converter that processes the digital signal in a frequency domain to generate a reduced digital data signal, the logic circuit processing the digital signal acquired from the converter to generate a continuous data transfer to a processing system.