Provided herein are devices, systems, and methods for characterizing a biological sample in vivo or ex vivo in real-time using time-resolved spectroscopy. A light source generates a light pulse or continuous light wave and excites the biological sample, inducing a responsive fluorescent signal. A demultiplexer splits the signal into spectral bands and a time delay is applied to the spectral bands so as to capture data with a detector from multiple spectral bands from a single excitation pulse. The biological sample is characterized by analyzing the fluorescence intensity magnitude and/or decay of the spectral bands. The sample may comprise one or more exogenous or endogenous fluorophore. The device may be a two-piece probe with a detachable, disposable distal end. The systems may combine fluorescence spectroscopy with other optical spectroscopy or imaging modalities. The light pulse may be focused at a single focal point or scanned or patterned across an area.

A derivative spectroscopy system for achieving a tunable resolution of 2 nm or less in resolving spectral components of an input optical signal is provided so as to estimate derivative spectra of the input optical signal based on the resolved spectral components. In the system, a first dispersive-element structure spectrally decomposes the input optical signal into subband signals. A second dispersive-element structure receives part or all of the subband signals and spectrally decomposes the received subband signals to plural spectral components. A material having a temperature-variant refractive index is used to build the second dispersive-element structure, enabling a shift of center wavelength of each spectral component as small as 2 nm of less upon changing a temperature of the second dispersive-element structure. By obtaining three spectral-component sets obtained at three different predetermined temperatures with the center-wavelength shift of 2 nm or less, first- and second-order derivative spectra are obtained with good accuracy.

A spectrometer for temporally separating electromagnetic radiation (10) includes a cavity (105) having first and second reflecting mirrors (1, 2, 4, 5). The first mirror (1, 2) has an aperture (8) arranged to allow electromagnetic radiation (10) to be input into the cavity (105). The spectrometer also includes an imaging device (3) between the first and second mirrors (1, 2, 4, 5) that defines an optical axis of the cavity (105) and performs spatial Fourier transforms of the electromagnetic radiation (10). The first and/or second mirrors (1, 2, 4, 5) has a normal that is arranged at a non-parallel angle to the optical axis, such that the position and/or angle of incidence of electromagnetic radiation (10) on the second mirror is shifted after each round trip. The second mirror (4, 5) allows a wavelength component (14) of the electromagnetic radiation to be output from the cavity (105) when the position and/or angle of incidence of the electromagnetic radiation on the second mirror (4) after one or more round trips of the cavity (105) exceeds a threshold.

A derivative spectroscopy system for achieving a tunable resolution of 2 nm or less in resolving spectral components of an input optical signal is provided so as to estimate derivative spectra of the input optical signal based on the resolved spectral components. In the system, a first dispersive-element structure spectrally decomposes the input optical signal into subband signals. A second dispersive-element structure receives part or all of the subband signals and spectrally decomposes the received subband signals to plural spectral components. A material having a temperature-variant refractive index is used to build the second dispersive-element structure, enabling a shift of center wavelength of each spectral component as small as 2 nm of less upon changing a temperature of the second dispersive-element structure. By obtaining three spectral-component sets obtained at three different predetermined temperatures with the center-wavelength shift of 2 nm or less, first- and second-order derivative spectra are obtained with good accuracy.

Light detection systems are provided. Aspects of the light detection systems include first and second light receivers in fixed positions relative to each other, a plurality of wavelength separators configured to pass light from the first and second light receivers having a predetermined spectral range, and a plurality of light detection modules. Baseplates having a stage for mounting a light receiver, a plurality of recesses for fixing a plurality of light detection modules in rigid alignment relative to the stage, and a heat dissipation opening positioned within each recess are also provided. In addition, particle analysis systems, methods and kits for practicing the invention are disclosed.

Provided herein are devices, systems, and methods for characterizing a biological sample in vivo or ex vivo in real-time using time-resolved spectroscopy. A light source generates a light pulse or continuous light wave and excites the biological sample, inducing a responsive fluorescent signal. A demultiplexer splits the signal into spectral bands and a time delay is applied to the spectral bands so as to capture data with a detector from multiple spectral bands from a single excitation pulse. The biological sample is characterized by analyzing the fluorescence intensity magnitude and/or decay of the spectral bands. The sample may comprise one or more exogenous or endogenous fluorophore. The device may be a two-piece probe with a detachable, disposable distal end. The systems may combine fluorescence spectroscopy with other optical spectroscopy or imaging modalities. The light pulse may be focused at a single focal point or scanned or patterned across an area.

Light detection systems are provided. Aspects of the light detection systems include first and second light receivers in fixed positions relative to each other, a plurality of wavelength separators configured to pass light from the first and second light receivers having a predetermined spectral range, and a plurality of light detection modules. Baseplates having a stage for mounting a light receiver, a plurality of recesses for fixing a plurality of light detection modules in rigid alignment relative to the stage, and a heat dissipation opening positioned within each recess are also provided. In addition, particle analysis systems, methods and kits for practicing the invention are disclosed.