A broadband interferometry for a measurement range extension beyond a coherence length of a light source includes a wavelength tunable laser as the light source outputting a coherence wavelength beam; and an interferometer disposed between the wavelength tunable laser and a target to be measured and including a reference arm, a measurement arm and a device combining a reference beam and measurement mean to produce a combined interference beam, wherein a local oscillation of the reference beam is replicated by a cavity multiplication or cascading optical delayed lines with a fiber optic cavity, and quantifiable optical properties including a wavelength group delay, a chromatic dispersion, a polarization mode dispersion and a model dispersion are inserted into the local oscillation of the reference beam to incrementally quantify the replicated copies of the local oscillation as the number of the delayed copies of the local oscillation increase for extension of a measurement rage to the target.

The invention relates to a method of inner light layer illumination for optical imaging and detection in turbid media and apparatuses designed based on this method. This invention uses multiple beam interference to create destructive interference in the propagation path to reduce the illumination beam intensity and so to reduce absorption and scattering of the turbid media, and to create constructive interference to produce composite light intensity maximum which forms an inner light layer to illuminate the object. The theoretical analyses and mathematical calculations have proved the feasibility of the method. The designed apparatuses have great performances. Compared with the traditional technology, this method can enhance the signal strength more than 600 dB. The imaging depth can be over 5 cm in human body, and more than 500 m in clear seawater. The imaging resolutions are <1 μm along object plane and approximate 1 μm along direction of depth of field.

The invention relates to a method of inner light layer illumination for optical imaging and detection in turbid media and apparatuses designed based on this method. This invention uses multiple beam interference to create destructive interference in the propagation path to reduce the illumination beam intensity and so to reduce absorption and scattering of the turbid media, and to create constructive interference to produce composite light intensity maximum which forms an inner light layer to illuminate the object. The theoretical analyses and mathematical calculations have proved the feasibility of the method. The designed apparatuses have great performances. Compared with the traditional technology, this method can enhance the signal strength more than 600 dB. The imaging depth can be over 5 cm in human body, and more than 500 m in clear seawater. The imaging resolutions are <1 μm along object plane and approximate 1 μm along direction of depth of field.

Disclosed is a heterodyne laser interferometer based on an integrated secondary beam splitting component, which belongs to the technical field of laser application; the disclosure inputs two beams that are spatially separated and have different frequencies to the heterodyne laser interferometer based on the integrated secondary beam splitting component, wherein the integrated secondary beam splitting component includes two beam splitting surfaces that are spatially perpendicular to each other; and the two beam splitting surfaces are plated with a polarizing beam splitting film or a non-polarizing beam splitting film, and a measurement beam and a reference beam are the same in travel path length in the integrated secondary beam splitting component. The heterodyne laser interferometer of the disclosure significantly reduces periodic nonlinear errors, has the advantages of simple structure, good thermal stability, large tolerance angle and easy integration and assembly compared with other existing heterodyne laser interferometers with spatially separated optical paths, and meets the high-precision and high-resolution requirements of high-end equipment on heterodyne laser interferometry.

A measurement system includes an optical probe that has a reflective prism structure, an input system, and an output system. The reflective prism structure comprises at least two mirrored surfaces on opposing sides of an axis which extends in a direction towards a target. The input system is positioned to receive and direct source light towards one of the mirrored surfaces which is positioned to reflect the source light towards the target. The output system is positioned to receive and output converging light from reflected light that comprises measurement data related to the target. The reflected light is the source light reflected from the target via the other one of the mirrored surfaces and is without substantial overlap with the source light.

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger the spectral output bandwidth under the equilibrium conditions.

Disclosed is a heterodyne laser interferometer based on an integrated secondary beam splitting component, which belongs to the technical field of laser application; the disclosure inputs two beams that are spatially separated and have different frequencies to the heterodyne laser interferometer based on the integrated secondary beam splitting component, wherein the integrated secondary beam splitting component includes two beam splitting surfaces that are spatially perpendicular to each other; and the two beam splitting surfaces are plated with a polarizing beam splitting film or a non-polarizing beam splitting film, and a measurement beam and a reference beam are the same in travel path length in the integrated secondary beam splitting component. The heterodyne laser interferometer of the disclosure significantly reduces periodic nonlinear errors, has the advantages of simple structure, good thermal stability, large tolerance angle and easy integration and assembly compared with other existing heterodyne laser interferometers with spatially separated optical paths, and meets the high-precision and high-resolution requirements of high-end equipment on heterodyne laser interferometry.

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger the spectral output bandwidth under the equilibrium conditions.

A measurement system includes an optical probe that has a reflective prism structure, an input system, and an output system. The reflective prism structure comprises at least two mirrored surfaces on opposing sides of an axis which extends in a direction towards a target. The input system is positioned to receive and direct source light towards one of the mirrored surfaces which is positioned to reflect the source light towards the target. The output system is positioned to receive and output converging light from reflected light that comprises measurement data related to the target. The reflected light is the source light reflected from the target via the other one of the mirrored surfaces and is without substantial overlap with the source light.

An interferometer system includes a measurement arm comprising a measurement dispersive optical system, a reference arm comprising a bulk diffuser object and a reference dispersive optical system, and an output system. The measurement dispersive optical system is positioned to direct measurement chromatic light towards a target, receive diverging chromatic measurement light from the target, and direct detected measurement light from the received diverging chromatic measurement light towards the output system. The reference dispersive optical system is positioned to direct reference chromatic light towards the bulk diffuser object, receive diverging chromatic reference light from the bulk diffuser object, and direct detected reference light from the received diverging chromatic reference light towards the output system. The output system is configured to determine at least one measured property of the target from the detected measurement light and the detected reference light.