The present disclosure relates to a collaborative phase-shift laser ranging device based on differential modulation and demodulation of coarse and precise measuring wavelength and a ranging method thereof. A collaboration terminal is disposed at a target to be measured of a phase-shift laser ranging system, which can improve the intensity of measurement light and then irradiate the same back to a measuring terminal, thereby resolving the problem of low ranging accuracy caused by the attenuation of light intensity during long-distance ranging. The collaboration terminal detects coarseness gauge signals and modulates a laser source by means of differential modulation; the collaboration terminal detects precision gauge signals by means of difference frequency demodulation, and then the intensity of measurement light is improved by mixing and restoring the precision gauge signals and modulating the collaboration-terminal laser source.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

A device includes a first component, a second component having a reconfigurable distance from the first component, an optical element, an SMI sensor, and a processor. The optical element has a fixed relationship with respect to the first component, and has a known optical thickness between a first surface and a second surface of the optical element. The SMI sensor has a fixed relationship with respect to the second component, and has an electromagnetic radiation emission axis that intersects the first and second surfaces of the optical element. The processor is configured to identify disturbances in an SMI signal generated by the SMI sensor, relate the disturbances to the known optical thickness of the optical element, and to determine a distance between the first and second components using the SMI signal and the relationship of the disturbances to the known optical thickness of the optical element.

To provide a distance and velocity measurement apparatus that can be adopted preferably in a LiDAR or a sensor for a robot, wherein the apparatus can prevent deterioration of SN ratio even in a case where an object in an external environment vibrates. A LiDAR 20 according to the present embodiment includes a first laser apparatus 1a, a second laser apparatus 1b, a polarization-maintaining type optical fiber 2, a WDM filter 6, an optical fiber coupler 3a, an optical amplifier 11, an input/output unit 4, an optical scanner 5, a second optical fiber coupler 3b, a balanced photodetector 7, and a square-law detector 9. Further, a delay line 10 composed of a polarization-maintaining optical fiber is provided on the local port 2b. The first laser apparatus 1a includes a device for generating a first laser light having a first wavelength and a first chirp rate in an interior thereof, and the second laser apparatus 1b includes a device for generating a second laser light having a second wavelength that differs from the first wavelength and a second chirp rate that differs from the first chirp rate.

A photonic circulator deployed on a chip-scale light-detection and ranging (LiDAR) device includes a first arm that includes a first waveguide that is bonded onto a first member at a first bonding region, and a second arm that includes a second waveguide that is bonded onto a second member at a second bonding region. A first thermo-optic phase shifter is arranged on the first member and collocated with the first waveguide, and a second thermo-optic phase shifter is arranged on the second member and collocated with the second waveguide. The magneto-optic material and the first thermo-optic phase shifter of the first member cause a first phase shift in a first light beam travelling through the first waveguide, and the magneto-optic material and the second thermo-optic phase shifter of the second member cause a second phase shift in a second light beam travelling through the second waveguide.

A laser sensor includes a laser source configured to emit a laser beam, and optics configured to project the laser beam as a one- or two-dimensional patterned laser beam onto an object to be examined, such that a distance of the patterned laser beam from the laser source varies along the patterned laser beam projected on the object. The laser sensor further includes a detector configured to determine a self-mixing interference signal generated by laser light of the patterned laser beam reflected from the object back into the laser source, and circuitry configured to analyze a spectrum of the self-mixing interference signal and extract from the spectrum of the self-mixing interference signal multiple frequencies that are indicative of at least one of the following: multiple distances along the patterned laser beam from the laser source, or multiple velocities along the patterned laser beam with respect to the laser source.

Self-mixing interferometry (SMI) sensors may include vertical cavity surface emitting lasers (VCSEL), photodetectors, and microelectromechanical systems (MEMS). The VCSEL, photodetectors, and MEMS may be vertically stacked. The MEMS may be moveable with respect to a VCSEL and may change a cavity length associated with the VCSEL. By changing the cavity length associated with the VCSEL, certain properties of emitted light may be changed, such as a wavelength value of the emitted light.

A method of estimating a velocity of an object using an SMI sensor. The method includes driving a light emitter of the SMI sensor with a chirped waveform. The chirped waveform includes a first chirp and a second chirp separated by a first time interval, and a third chirp separated from the second chirp by a second time interval. The method also includes deriving a frequency-based velocity from an output of the SMI sensor; generating a first comb of possible velocities in response to analyzing an output of the SMI sensor generated in response to the first chirp and the second chirp; generating a second comb of possible velocities in response to analyzing an output of the SMI sensor generated in response to the second chirp and the third chirp; and determining a velocity of the object using the first comb, the second comb, and the frequency-based velocity.

The present invention provides a measuring apparatus and a measuring method in which a relative moving velocity of a target to be measured or a separation displacement of the target to be measured can be accurately measured even in a case where the target to be measured is moved. In a measuring apparatus, a relative moving velocity of a target to be measured and a separation displacement of the target to be measured can be measured in consideration of the influence of Doppler shift that occurs due to the movement of the target to be measured in an in-plane direction, and thus, even in a case where the target to be measured is moved in the in-plane direction, the relative moving velocity of the target to be measured and the separation displacement of the target to be measured can be accurately measured.

An optical proximity sensor includes an optical path extender that extends an optical path length of the optical proximity sensor without a corresponding extension of a geometric path length of the optical proximity sensor. The optical path extender may be a high-refractive index material positioned along the optical path through the optical proximity sensor. The optical path extender may include one or more redirection features configured to change a direction of the light traveling within the optical proximity sensor. The optical path extender may include a photonic component configured to simulate an extension of the geometric path within an optical proximity sensor by applying a momentum-dependent transfer function to the light traveling through it.