LIDAR systems are less accurate in the presence of background light which can saturate the sensors in the LIDAR system. The embodiments herein describe a LIDAR system with a shutter synchronized to a laser source. During a first time period, the laser source is synched with the shutter so that the reflections are received when the shutter is in the process of changing between on and off states, during which time a function of the shutter (e.g., a phase retardation or opacity) monotonically changes so that reflections received at different times have different time-dependent characteristics (e.g., different polarizations). To mitigate the effects of background light, during a second time period, the laser source is synched with the shutter so that the background light is measured (in the absence of the reflections) which can be used to remove the effects of the background light from a range measurement.

LIDAR systems are less accurate in the presence of background light which can saturate the sensors in the LIDAR system. The embodiments herein describe a LIDAR system with a shutter synchronized to a laser source. During a first time period, the laser source is synched with the shutter so that the reflections are received when the shutter is in the process of changing between on and off states, during which time a function of the shutter (e.g., a phase retardation or opacity) monotonically changes so that reflections received at different times have different time-dependent characteristics (e.g., different polarizations). To mitigate the effects of background light, during a second time period, the laser source is synched with the shutter so that the background light is measured (in the absence of the reflections) which can be used to remove the effects of the background light from a range measurement.

A LiDAR apparatus includes a first substrate, a laser diode on a surface of the substrate for outputting light, a fast axis collimator (FAC) lens receiving the light and generating an at least partially collimated light beam, a polarizing beam splitter optically coupled to the FAC lens, at least a portion of the light beam passing through the polarizing beam splitter to a region being observed by the LiDAR apparatus. An opaque coating on the back side of an aperture element coupled to the polarizing beam splitter is patterned to provide a transparent aperture. At least a portion of light returning to the LiDAR apparatus from the region being observed is directed by the polarizing beam splitter, through the transparent aperture in the opaque coating on the aperture element, through the at least partially reflective optical element to an optical detector mounted on the substrate.

A LiDAR system has a field of view and includes a polarization-based waveguide splitter. The splitter includes a first splitter port, a second splitter port and a common splitter port. A laser is optically coupled to the first splitter port via a single-polarization waveguide. An objective lens optically couples each optical emitter of an array of optical emitters to a respective unique portion of the field of view. An optical switching network is coupled via respective dual-polarization waveguides between the common splitter port and the array of optical emitters. An optical receiver is optically coupled to the second splitter port via a dual-polarization waveguide and is configured to receive light reflected from the field of view. A controller, coupled to the optical switching network, is configured to cause the optical switching network to route light from the laser to a sequence of the optical emitters according to a temporal pattern.

A light detection and ranging (LIDAR) sensor system includes a dual-polarization optical antenna, a single-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna is configured to (i) emit a transmit beam with a first polarization orientation and (ii) and detect a return beam having a second polarization orientation. The single-polarization optical antenna is configured to detect the return beam having the second polarization orientation.

A light detection and ranging (LIDAR) sensor system includes a dual-polarization optical antenna, a single-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna is configured to (i) emit a transmit beam with a first polarization orientation and (ii) and detect a return beam having a second polarization orientation. The single-polarization optical antenna is configured to detect the return beam having the second polarization orientation.

Improved resolution of a time-varying optical image is provided with a wide field optical intensity modulator having a bandwidth greater than that of the detector array(s). The modulator configuration can have high photon collection efficiency, e.g. by using polarization modulation to split the incident light into several timegated channels.

A position reference sensor (100) has a light source (120), a detector (160) and a processor (170). The light source (120) is configured to emit light having a first component and a second component. The detector (160) is configured to detect reflected light. The processor (170) is configured to determine a distance between the position reference sensor (100) and a target based on the emitted light and the detected reflected light. The processor (170) is also configured to determine that the target is a selective retroreflector (140) based on the intensity of the first component of the light in the detected reflected light and the intensity of the second component of the light in the detected reflected light.

A position reference sensor (100) has a light source (120), a detector (160) and a processor (170). The light source (120) is configured to emit light having a first component and a second component. The detector (160) is configured to detect reflected light. The processor (170) is configured to determine a distance between the position reference sensor (100) and a target based on the emitted light and the detected reflected light. The processor (170) is also configured to determine that the target is a selective retroreflector (140) based on the intensity of the first component of the light in the detected reflected light and the intensity of the second component of the light in the detected reflected light.

The invention provides a sensing system (1000), e.g. for agricultural application, comprising a radiation generator (100), a sensing apparatus (200), and a control system (300) functionally coupled to the radiation generator (100) and the sensing apparatus (200), wherein the sensing system (1000) has one or more time-of-flight sensing modes of operation, wherein the generator (100) is configured to generate a pulse of radiation (111) in the one or more time-of-flight sensing modes of operation, and wherein the sensing apparatus (200) is configured to sense wavelength dependent spectral intensities of radiation received by the sensing apparatus (200) as a function of time in the one or more time-of-flight sensing modes, to provide a sensing system signal; wherein the sensing system signal is indicative of the wavelength dependent spectral intensity distribution of the received radiation as a function of time in the one or more time-of-flight sensing modes.