Provided are a time and frequency control method and system for optical comb. The method includes: controlling an optical comb measuring system to start and to generate an optical comb; obtaining monitoring data, wherein the monitoring data comprises a working temperature, a mode-locked frequency and a light pump power, wherein the mode-locked frequency comprises a repetition frequency and a carrier envelope phase locked at the end of starting the optical comb measuring system; determining whether an offset of the mode-locked frequency exceeds a self-feedback adjustment range of a hardware adjustment circuit; and in response to any of the repetition frequency and the carrier envelope phase exceeds the self-feedback adjustment range, adjusting the working temperature and the light pump power until the mode-locked frequency returns back into the self-feedback adjustment range.

A remote sampling sensor for determining characteristics of a sample includes measurement optics and an insertion probe. The measurement optics are configured to emit light and detect returned light. The insertion probe includes a chamber, the chamber being configured to permit the sample to enter the chamber, an insertion tip at a distal end of the insertion probe, and a retro-reflective optic adjacent the insertion tip. The retro-reflective optic is configured to return the light from the measurement optics through the chamber to the measurement optics. The insertion probe is configured to be remotely located from the measurement optics.

A remote sampling sensor for determining characteristics of a sample includes measurement optics and an insertion probe. The measurement optics are configured to emit light and detect returned light. The insertion probe includes a chamber, the chamber being configured to permit the sample to enter the chamber, an insertion tip at a distal end of the insertion probe, and a retro-reflective optic adjacent the insertion tip. The retro-reflective optic is configured to return the light from the measurement optics through the chamber to the measurement optics. The insertion probe is configured to be remotely located from the measurement optics.

Optical imaging or spectroscopy described can use laminar optical tomography (LOT), diffuse correlation spectroscopy (DCS), or the like. An incident beam is scanned across a target. An orthogonal or oblique optical response can be obtained, such as concurrently at different distances from the incident beam. The optical response from multiple incident wavelengths can be concurrently obtained by dispersing the response wavelengths in a direction orthogonal to the response distances from the incident beam. Temporal correlation can be measured, from which flow and other parameters can be computed. An optical conduit can enable endoscopic or laparoscopic imaging or spectroscopy of internal target locations. An articulating arm can communicate the light for performing the LOT, DCS, or the like. The imaging can find use for skin cancer diagnosis, such as distinguishing lentigo maligna (LM) from lentigo maligna melanoma (LMM).

Optical imaging or spectroscopy described can use laminar optical tomography (LOT), diffuse correlation spectroscopy (DCS), or the like. An incident beam is scanned across a target. An orthogonal or oblique optical response can be obtained, such as concurrently at different distances from the incident beam. The optical response from multiple incident wavelengths can be concurrently obtained by dispersing the response wavelengths in a direction orthogonal to the response distances from the incident beam. Temporal correlation can be measured, from which flow and other parameters can be computed. An optical conduit can enable endoscopic or laparoscopic imaging or spectroscopy of internal target locations. An articulating arm can communicate the light for performing the LOT, DCS, or the like. The imaging can find use for skin cancer diagnosis, such as distinguishing lentigo maligna (LM) from lentigo maligna melanoma (LMM).

A device that uses two intensity modulated frequency combs to measure distances with high precision and high data acquisition rate without any moving parts and without length ambiguity that is inherent conventional ranging based on two frequency combs. A modulation signal having a repetition rate identical to the repetition rate difference between the two combs is used to do a direct time-of-flight length measurement, hence avoiding the given length ambiguity while harvesting the increased precision of the dual-comb approach.

A device that uses two intensity modulated frequency combs to measure distances with high precision and high data acquisition rate without any moving parts and without length ambiguity that is inherent conventional ranging based on two frequency combs. A modulation signal having a repetition rate identical to the repetition rate difference between the two combs is used to do a direct time-of-flight length measurement, hence avoiding the given length ambiguity while harvesting the increased precision of the dual-comb approach.

A frequency-measurement method uses a dual frequency-comb spectrometer as an optical wavemeter to measure the frequency of a reference laser that is used to frequency-stabilize the spectrometer. The method includes measuring a walking rate of center bursts in a sequence of interferograms recorded by the spectrometer, determining a number of teeth in each of a plurality of Nyquist windows formed by the dual frequency-comb spectrometer, and determining a Nyquist number of the one Nyquist window covering the laser frequency. The reference laser frequency can then be determined from the number of teeth in each Nyquist window, the Nyquist number, and the comb spacing of either one of the two frequency combs of the dual frequency-comb spectrometer. The reference laser frequency does not need to be measured with a separate wavemeter, or calibrated with respect to a known atomic or molecular transition.

A light wavelength measurement method of measuring a wavelength of target light includes: receiving target light on a second dispersion device that disperses the target light into a plurality of second beams which reach a plurality of positions corresponding to the wavelength of the target light (S106, S202); and measuring the wavelength of the target light, by using the plurality of the second beams as a vernier scale for measuring the wavelength of the target light within a wavelength range specified by a main scale (S108, S204).

A light wavelength measurement method of measuring a wavelength of target light includes: receiving target light on a second dispersion device that disperses the target light into a plurality of second beams which reach a plurality of positions corresponding to the wavelength of the target light (S106, S202); and measuring the wavelength of the target light, by using the plurality of the second beams as a vernier scale for measuring the wavelength of the target light within a wavelength range specified by a main scale (S108, S204).