An endoscopic imaging system for use in a light deficient environment includes an imaging device having a tube, one or more image sensors, and a lens assembly including at least one optical elements that corresponds to the one or more image sensors. The endoscopic system includes a display for a user to visualize a scene and an image signal processing controller. The endoscopic system includes a light engine having an illumination source generating one or more pulses of electromagnetic radiation and a lumen transmitting one or more pulses of electromagnetic radiation to a distal tip of an endoscope.

Systems for measuring optical properties of a specimen are disclosed. The systems are configured to sample signals related to the measurement of the properties of a specimen, and perform software-based coherent detection of the signals to generate resulting measurements are based on the signals acquired at substantially the same time instance. This facilitates the displaying or generating of the desired measurements in real time. In one configuration, the system is configured to direct a modulated light signal at a selected wavelength incident upon a specimen. In another configuration, the system is configured to direct a combined light signal, derived from a plurality of light signals at different wavelengths and modulated with different frequencies, incident upon a specimen. In yet another configuration, the system is configured to direct a plurality of light signals modulated with different frequencies incident upon different regions of a specimen.

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.

An ultrahigh-resolution mid-infrared (MIR) dual-comb spectroscopy (DCS) measurement device includes a pump unit, a microring resonator (MRR) unit, a modulation unit, a splitting unit, a testing unit, a signal detection unit, a power balance unit, a reference detection unit and a spectral analysis unit. The measurement method includes: adjusting the laser emitted by the pump unit to the MRR unit; adjusting the modulation unit and performing dual-frequency modulation; generating two sets of MIR optical frequency combs (OFCs) with different repetition rates and splitting the MIR OFCs into the test light and the reference light; performing photoelectric conversion on the test light and injecting the test light to the spectral analysis unit; performing photoelectric conversion on the reference light and injecting the reference light to the spectral analysis unit; and performing Fourier transformation and data processing on test results to obtain absorption spectrum of the to-be-tested sample.

A terahertz light detector includes: a light reception unit that receives terahertz light from a measured object; a pulse laser that generates pulse light; an optical member which the pulse light enters; and a control unit that controls the energy of the pulse light which enters the optical member, wherein the optical member has anomalous dispersion, and the light reception unit outputs a signal that is dependent on an intensity of terahertz light when the pulse light emitted from the optical member enters the light reception unit.

Method and gas analyzer for measuring the concentration of a gas component in a measurement gas, a wavelength-tunable laser diode is actuated with a current, one part of the light generated by the laser diode is guided through the measurement gas to a measuring detector to generate a measuring signal, the other part of the light is guided to a monitor detector to generate a monitor signal, the current is varied in periodically consecutive scanning intervals to scan an absorption line of interest of the gas component as a function of the wavelength, the current is further modulated with a radio-frequency noise signal having a lower cut-off frequency selected as a function of the properties of the laser diode and high enough to ensure no wavelength modulation occurs and the measuring signal is correlated with the monitor signal and then evaluated to generate a measurement result.

A measuring apparatus for measuring a spectrum of a gaseous sample includes a tunable laser light source to provide an illuminating light beam, a sample cell with an inner surface to provide scrambled light that is transmitted through the gaseous sample, a detector to detect intensity of transmitted scrambled light and a pressure control system to maintain an absolute pressure of the gaseous sample smaller than 50 kPa inside the sample cell to reduce spectral widths of spectral features of the gaseous sample. The measuring apparatus measures spectral transmittance values of the sample by modulating the spectral position of the illuminating light, and detecting the intensity of the transmitted light at different spectral positions. The divergence of the illuminating light beam in a transverse direction is greater than 30° to cause multiple consecutive reflections of the scrambled light from the inner surface.

Modulation-encoded light, using different spectral bin coded light components, can illuminate a stationary or moving (relative) target object or scene. Response signal processing can use information about the respective different time-varying modulation functions, to decode to recover information about a respective response parameter affected by the target object or scene. Electrical or optical modulation encoding can be used. LED-based spectroscopic analysis of a composition of a target (e.g., SpO2, glucose, etc.) can be performed; such can optionally include decoding of encoded optical modulation functions. Baffles or apertures or optics can be used, such as to constrain light provided by particular LEDs. Coded light illumination can be used with a focal plane array light imager receiving response light for inspecting a moving semiconductor or other target. Encoding can use orthogonal functions, such as an RGB illumination sequence, or a sequence of combinations of spectrally contiguous or non-contiguous colors.

In swept source Raman (SSR) spectroscopy, a swept laser beam illuminates a sample, which inelastically scatters some of the incident light. This inelastically scattered light is shifted in wavelength by an amount called the Raman shift. The Raman-shifted light can be measured with a fixed spectrally selective filter and a detector. The Raman spectrum can be obtained by sweeping the wavelength of the excitation source and, therefore, the Raman shift. The resolution of the Raman spectrum is determined by the filter bandwidth and the frequency resolution of the swept source. An SSR spectrometer can be smaller, more sensitive, and less expensive than a conventional Raman spectrometer because it uses a tunable laser and a fixed filter instead of free-space propagation for spectral separation. Its sensitivity depends on the size of the collection optics. And it can use a nonlinearly swept laser beam thanks to a wavemeter that measures the beam's absolute wavelength during Raman spectrum acquisition.

An ultrahigh-resolution mid-infrared (MIR) dual-comb spectroscopy (DCS) measurement device includes a pump unit, a microring resonator (MRR) unit, a modulation unit, a splitting unit, a testing unit, a signal detection unit, a power balance unit, a reference detection unit and a spectral analysis unit. The measurement method includes: adjusting the laser emitted by the pump unit to the MRR unit; adjusting the modulation unit and performing dual-frequency modulation; generating two sets of MIR optical frequency combs (OFCs) with different repetition rates and splitting the MIR OFCs into the test light and the reference light; performing photoelectric conversion on the test light and injecting the test light to the spectral analysis unit; performing photoelectric conversion on the reference light and injecting the reference light to the spectral analysis unit; and performing Fourier transformation and data processing on test results to obtain absorption spectrum of the to-be-tested sample.