Abstract: A method is provided for characterizing a biological sample having a plurality of fluorophores, including a red fluorophore and a blue fluorophore, comprises exciting the red fluorophore via absorption of a photon order of n by a single wavelength band of light that has longer wavelengths than a typical wavelength band of light known to excite the red fluorophore would have. The method further comprises exciting the blue fluorophore substantially via absorption of a photon order of n+1 by the single wavelength band of light. The method also comprises simultaneously detecting light emitted by the red fluorophore and the blue fluorophore. The method further comprises creating an image or a temporal series for sensing from the light detected in the plurality of orthogonal colors.

Abstract: Methods for label-free characterization of untagged molecules within a biological sample in-situ. The untagged molecules may be constituent of extracellular vesicles, and are excited in the biological sample with at least one wavelength band of light derived from a single stream of optical pulses. Light emitted by the untagged molecules by SHG, THG, 2PAF and 3PAF processes is detected. Separate measures of the biological sample corresponding to light emitted by the untagged molecules in each of the SHG, THG, 2PAF and 3PAF processes are derived. On that basis, normal extracellular vesicles may be differentiated from extracellular vesicles associated with a tumor on the basis of a specified signature of characteristics of images of SHG, THG, 2PAF and 3PAF processes.

Abstract: Methods for label-free characterization of untagged molecules within a biological sample in-situ. The untagged molecules may be constituent of extracellular vesicles, and are excited in the biological sample with at least one wavelength band of light derived from a single stream of optical pulses. Light emitted by the untagged molecules by SHG, THG, 2PAF and 3PAF processes is detected. Separate measures of the biological sample corresponding to light emitted by the untagged molecules in each of the SHG, THG, 2PAF and 3PAF processes are derived. On that basis, normal extracellular vesicles may be differentiated from extracellular vesicles associated with a tumor on the basis of a specified signature of characteristics of images of SHG, THG, 2PAF and 3PAF processes.

Abstract: Methods and apparatus for generating ultrashort optical pulses. Pulses of an infrared source are launched into an optical fiber characterized by a zero-dispersion wavelength (ZDW), where the wavelength of the infrared source exceeds the ZDW of the optical fiber by at least 100 nm. A resonant dispersion wave (RDW) is generated in the optical fiber that has a central wavelength blue-shifted by more than 500 nm relative to the pump wavelength, and, in some cases, by more than 700 nm. The optical fiber has a core of a diameter exceeding the central wavelength of the RDW by at least a factor of five. In a preferred embodiment, the infrared source includes a master-oscillator-power-amplifier, embodied entirely in optical fiber, and may include an Erbium:fiber oscillator, in particular.

Abstract: Methods and apparatus for generating ultrashort optical pulses. Pulses of an infrared source are launched into an optical fiber characterized by a zero-dispersion wavelength (ZDW), where the wavelength of the infrared source exceeds the ZDW of the optical fiber by at least 100 nm. A resonant dispersion wave (RDW) is generated in the optical fiber that has a central wavelength blue-shifted by more than 500 nm relative to the pump wavelength, and, in some cases, by more than 700 nm. The optical fiber has a core of a diameter exceeding the central wavelength of the RDW by at least a factor of five. In a preferred embodiment, the infrared source includes a master-oscillator-power-amplifier, embodied entirely in optical fiber, and may include an Erbium:fiber oscillator, in particular.

Abstract: Methods and apparatus for generating ultrashort optical pulses. Polarized pulses of a near-infrared source are launched substantially along a principle axis of a birefringent photonic crystal fiber characterized by normal dispersion at all wavelengths of transmission of the photonic crystal fiber. Supercontinuum pulses are generated from the photonic crystal fiber and compressed to form compressed pulses. Highly polarized supercontinuum pulses provide for transform-limited compressed pulse durations.

Abstract: An apparatus and methods for generating a substantially supercontinuum-free widely-tunable multimilliwatt source of radiation characterized by a narrowband line profile. The apparatus and methods employ nonlinear optical mechanisms in a nonlinear photonic crystal fiber (PCF) by detuning the wavelength of a pump laser to a significant extent relative to the zero-dispersion wavelength (ZDW) of the PCF. Optical phenomena employed for the selective up-conversion in the PCF include, but are not limited to, four-wave mixing and Cherenkov radiation. Tunability is achieved by varying pump wavelength and power and by substituting different types of PCFs characterized by specified dispersion properties.

Abstract: Methods and apparatus for generating ultrashort optical pulses. Polarized pulses of a near-infrared source are launched substantially along a principle axis of a birefringent photonic crystal fiber characterized by normal dispersion at all wavelengths of transmission of the photonic crystal fiber. Supercontinuum pulses are generated from the photonic crystal fiber and compressed to form compressed pulses. Highly polarized supercontinuum pulses provide for transform-limited compressed pulse durations.

Abstract: An apparatus and methods for generating a substantially supercontinuum-free widely-tunable multimilliwatt source of radiation characterized by a narrowband line profile. The apparatus and methods employ nonlinear optical mechanisms in a nonlinear photonic crystal fiber (PCF) by detuning the wavelength of a pump laser to a significant extent relative to the zero-dispersion wavelength (ZDW) of the PCF. Optical phenomena employed for the selective up-conversion in the PCF include, but are not limited to, four-wave mixing and Cherenkov radiation. Tunability is achieved by varying pump wavelength and power and by substituting different types of PCFs characterized by specified dispersion properties.